1 Sys_Parameters Help is provided for the system parameters listed below. 2 ACP_BASEPRIO ACP_BASEPRIO sets the base priority for all ACPs. The DCL command SET PROCESS/PRIORITY can be used to reset the base priorities of individual ACPs. ACP_BASEPRIO is not applicable for XQPs. ACP_BASEPRIO is a DYNAMIC parameter. 2 ACP_DATACHECK ACP_DATACHECK controls the consistency checks that are performed on internal file system metadata such as file headers. ACP_DATACHECK is a bit mask. The following table shows the bits that are defined currently: Bit Description 0 Set this bit to perform consistency checks on read operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_ READLBLK operations that read file system metadata (see the OpenVMS I/O User's Reference Manual). 1 Set this bit to perform consistency checks on write operations. When this bit is set, the IO$M_DATACHECK function modifier is automatically set on all subsequent IO$_ WRITELBLK operations that read file system metadata (see the OpenVMS I/O User's Reference Manual). 2 Set this bit to perform read-after-write consistency checks. This is similar to setting bit 1, except that in this case the file system does the checks, not the lower level device or disk driver. Note that read-after-write consistency checks are not allowed on deferred writes. Deferred writes are turned off if this bit is set. 3 reserved for VSI use only; must be zero. 4 reserved for VSI use only; must be zero. 5 and 6 These two bits control the checks that are performed on reads and writes of directory blocks. You can select one of four different levels: By Select Setting This Bit 6 And Bit 5 To Check That... Level... to... to... The block is a valid 0 0 0 directory block (reads only) The block is a valid 1 0 1 directory block (reads and writes) The block is a valid 2 1 0 directory block and contains valid entries (reads and writes) The block is a valid 3 1 1 directory block and contains valid entries in correct alphanumeric order (reads and writes) When you set the SYSTEM_CHECK system parameter to 1, you enable level 3 checking of directory blocks. Write errors result in BUGCHECK and crash your system; read errors exit with error status SS$_BADDIRECTORY. 7 reserved for VSI use only; must be zero. 2 ACP_DINDXCACHE ACP_DINDXCACHE controls the size of the directory index cache and the number of buffers used on a cachewide basis. Also, ACP_DINDXCACHE builds a temporary index into the directory file, thereby reducing search time and directory header lookup operations. ACP_DINDXCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_DIRCACHE ACP_DIRCACHE sets the number of pages for caching directory blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the directory data block cache. ACP_DIRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_EXTCACHE ACP_EXTCACHE sets the number of entries in the extent cache. Each entry points to one contiguous area of free space on disk. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the extent cache. ACP_EXTCACHE is a DYNAMIC and FEEDBACK parameter. 2 ACP_EXTLIMIT ACP_EXTLIMIT specifies the maximum amount of free space to which the extent cache can point, expressed in thousandths of the currently available free blocks on the disk. For example, if available free space on the disk is 20,000 blocks, a specification of 10 limits the extent cache to 200 blocks. The computed, installed value is usually adequate. Users with four or more OpenVMS Cluster node systems might want to adjust this parameter. ACP_EXTLIMIT is a DYNAMIC parameter. 2 ACP_FIDCACHE ACP_FIDCACHE sets the number of file identification slots cached. A specification of 1 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FID caches. ACP_FIDCACHE is a DYNAMIC and FEEDBACK parameter. 2 ACP_HDRCACHE ACP_HDRCACHE sets the number of pages for caching file header blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the file header caches. ACP_HDRCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_MAPCACHE ACP_MAPCACHE sets the number of pages for caching index file bitmap blocks. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the bitmap cache. ACP_MAPCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_MAXREAD ACP_MAXREAD sets the maximum number of directory blocks read in one I/O operation. ACP_MAXREAD is a DYNAMIC parameter. 2 ACP_MULTIPLE ACP_MULTIPLE enables (1) or disables (0) the default creation of a separate disk XQP cache for each volume mounted on a different device type. Prior to Version 4.0, a separate ACP process was created for each device type if this parameter was enabled. Because ACP operations are now handled by the per process XQP, such separate processes are no longer created. In general, having multiple caches is unnecessary. One large cache is more efficient than several small ones. ACP_MULTIPLE can be overridden on an individual-volume basis with the DCL command MOUNT. ACP_MULTIPLE is an AUTOGEN and DYNAMIC parameter. 2 ACP_QUOCACHE ACP_QUOCACHE sets the number of quota file entries cached. A specification of 0 means no cache. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the quota caches. ACP_QUOCACHE is an AUTOGEN, DYNAMIC, and FEEDBACK parameter. 2 ACP_REBLDSYSD ACP_REBLDSYSD specifies whether the system disk should be rebuilt if it was improperly dismounted with extent caching, file number caching, or disk quota caching enabled. The ACP_REBLDSYSD default value (1) ensures that the system disk is rebuilt. Setting the value to 0 means the disk is not rebuilt. Depending on the amount of caching enabled on the volume before it was dismounted, the rebuild operation may consume a considerable amount of time. Setting the value of ACP_REBLDSYSD to 0 specifies that the disk should be returned to active service immediately. If you set ACP_REBLDSYSD to 0, you can enter the DCL command SET VOLUME/REBUILD at any time to rebuild the disk. 2 ACP_SHARE ACP_SHARE enables (0) or disables (1) the creation of a global section for the first ACP used, enabling succeeding ACPs to share its code. This parameter should be set to 0 when ACP_MULTIPLE is on. ACP_SHARE is a DYNAMIC parameter. 2 ACP_SWAPFLGS ACP_SWAPFLGS enables or disables swap through the value of a 4-bit number for the following four classes of ACPs: Bit Class of ACP 0 Disks mounted by MOUNT/SYSTEM 1 Disks mounted by MOUNT/GROUP 2 Private disks 3 Magnetic tape ACP If the value of the bit is 1, the corresponding class of ACPs can be swapped. The value of decimal 15 (hexadecimal F-all bits on) enables swap for all classes of ACP. A value of decimal 14 disables swap for ACPs for volumes mounted with the /SYSTEM qualifier but leaves swap enabled for all other ACPs. Note that one has only disk ACPs present if they are specifically requested at mount time or if a Files-11 On-Disk Structure Level 1 disk is mounted. In general, only bit 3 is significant because usually no file ACPs exist. ACP_SWAPFLGS is an AUTOGEN and DYNAMIC parameter. 2 ACP_SYSACC ACP_SYSACC sets the number of directory file control blocks (FCBs) that are cached for disks mounted with the /SYSTEM qualifier. Each directory FCB contains a 16-byte array containing the first letter of the last entry in each block of the directory (or group of blocks if the directory exceeds 16 blocks). Since entries in a directory are alphabetical, the cached FCB provides quick access to a required directory block. This parameter value should be roughly equivalent to the number of directories that are in use concurrently on each system volume. It might be overridden on a per-volume basis with the /ACCESSED qualifier to the DCL command MOUNT. The value should be kept low in systems with small physical memory and little file activity, because the FCBs require a significant amount of space in the nonpaged dynamic pool. Too small a value causes excessive XQP I/O operations, while too large a value causes excessive physical memory to be consumed by the FCB caches. ACP_SYSACC is an AUTOGEN and DYNAMIC parameter. 2 ACP_WINDOW ACP_WINDOW sets the default number of window pointers to be allocated in a window for a default file access, for disks mounted with the /SYSTEM qualifier. ACP_WINDOW is a DYNAMIC parameter. 2 ACP_WORKSET ACP_WORKSET sets the default size of a working set for an ACP. A specification of 0 permits the ACP to calculate the size. This value should be nonzero only on small systems where memory is tight. Too small a value causes excessive ACP page, while too large a value causes excessive physical memory to be consumed by the ACP. Note that this parameter has no effect on the per- process XQP. ACP_WORKSET is a DYNAMIC parameter. 2 ACP_WRITEBACK ACP_WRITEBACK is a dynamic system parameter that controls whether deferred writes to file headers are enabled. The default value is 1, which enables deferred writes to file headers. To disable the feature, set ACP_WRITEBACK to 0. This system parameter affects only applications like PATHWORKS that can request deferred writes to file headers. Note that the deferred write feature is not available on Files-11 ODS-1 volumes. ACP_WRITEBACK is a DYNAMIC parameter. 2 ACP_XQP_RES ACP_XQP_RES controls whether the XQP is currently in memory. The default value (1) specifies that the XQP is permanently in memory. Change the default only on restricted memory systems with a small number of users and little or no file activity that requires XQP intervention. Such activity includes file opens, closes, directory lookups, and window turns. 2 AFFINITY_SKIP AFFINITY_SKIP controls the breaking of implicit affinity. The value indicates the number of times a process is skipped before being moved. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 AFFINITY_TIME AFFINITY_TIME controls the breaking of implicit affinity. The value indicates how long a process remains on the compute queue. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 ALLOCLASS ALLOCLASS determines the device allocation class for the system. The device allocation class is used to derive a common lock resource name for multiple access paths to the same device. 2 ARB_SUPPORT (Alpha and Integrity servers) The Access Rights Block (ARB) compatibility option, the ARB_SUPPORT system parameter, is provided specifically to support products that have not yet been updated to use the new per-thread security Persona Security Block (PSB) data structure instead of the ARB. Changing the value of ARB_SUPPORT from 2 or 3 (the default) to any other value can affect the operation of these products. NOTE VSI recommends that all Version 7.3-1 systems have the ARB_SUPPORT parameter set to 3 (the default). Do not change the ARB_SUPPORT parameter to any other value until all products dependent on the ARB and associated structures have been modified for the new environment. The following table describes ARB_SUPPORT parameters: ARB_SUPPORT Parameter Value Behavior ISS$C_ARB_NONE 0 The obsolete kernel data cells are not maintained by the system. Fields are initialized to zero (or set to invalid pointers) at process creation. ISS$C_ARB_CLEAR 1 The obsolete kernel data cells are cleared (or set to invalid pointers) when the code would have set up values for backward compatibility. ISS$C_ARB_READ_ 2 The obsolete cells are updated with ONLY corresponding security information stored in the current PSB when a $PERSONA_ASSUME is issued. ISS$C_ARB_FULL 3 (de- Data is moved from the obsolete cells fault) to the currently active PSB on any security-based operation. ARB_SUPPORT is a DYNAMIC parameter. 2 AUTO_DLIGHT_SAV AUTO_DLIGHT_SAV is set to either 1 or 0. The default is 0. If AUTO_DLIGHT_SAV is set to 1, OpenVMS automatically makes the change to and from daylight saving time. 2 AWSMIN On Alpha and Integrity servers, AWSMIN establishes the lowest number of pagelets to which a working set limit can be decreased by automatic adjustment of the working set. AWSMIN is a DYNAMIC parameter. 2 AWSTIME AWSTIME specifies the minimum amount of processor time that must elapse for the system to collect a significant sample of a working set's page fault rate. The time is expressed in units of 10 milliseconds. The default value of 5, for example, is 50 milliseconds. Some application configurations that have a large number of memory-intensive processes may benefit if the value is reduced. The value can be as low as 4. AWSTIME expiration is checked only at quantum end. Reducing its value and not reducing QUANTUM effectively sets the value of AWSTIME equal to the value of QUANTUM. AWSTIME is a DYNAMIC parameter. 2 BALSETCNT BALSETCNT sets the number of balance set slots in the system page table. Each memory-resident working set requires one balance set slot. You can monitor the active system with the DCL command SHOW MEMORY or the MONITOR PROCESSES command of the Monitor utility to determine the actual maximum number of working sets in memory. If this number is significantly lower than the value of BALSETCNT, this parameter value could be lowered. If all balance set slots are being used, raise the value of BALSETCNT. Never set BALSETCNT to a value higher than 2 less than MAXPROCESSCNT. If physical memory is a significant system constraint, consider lowering this value even further. However, if your system runs with a number of processes nearly equal to MAXPROCESSCNT, lowering BALSETCNT forces swapping to occur, which can affect system performance. BALSETCNT is no longer a strict setting of the number of processes that might be resident in memory. The swapper tries to reduce the number of resident processes down to BALSETCNT. However, if the total number of active processes and processes that have disabled swapping exceeds BALSETCNT, the swapper does not force processes out of memory just to meet the BALSETCNT setting. BALSETCNT is an AUTOGEN, GEN, DYNAMIC, and MAJOR parameter. 2 BORROWLIM BORROWLIM defines the minimum number of pages required on the free-page list before the system permits process growth beyond the working set quota (WSQUOTA) for the process. This parameter should always be greater than FREELIM. This parameter allows a process to grow beyond the value set by the working set quota (WSQUOTA) to the working set quota extent (WSEXTENT) on a system that has a substantial memory on the free- page list. This automatic working set adjustment also depends upon the values of parameters WSINC, PFRATH, and AWSTIME. Working set growth attempts to alleviate heavy page faulting. To make use of this growth, you must also set the user's WSEXTENT authorization quota to a larger number than the WSQUOTA value. BORROWLIM is an AUTOGEN, DYNAMIC and MAJOR parameter. 2 BREAKPOINTS If XDELTA is loaded, BREAKPOINTS enables additional built-in calls for XDELTA during the boot sequence. The breakpoints that are enabled may change from release to release of OpenVMS. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. BREAKPOINTS is a DYNAMIC parameter. 2 BUGCHECKFATAL BUGCHECKFATAL enables or disables the conversion of nonfatal bugchecks into fatal bugchecks. The system must be rebooted on a fatal bugcheck. A nonfatal bugcheck places an entry only in the error log and deletes the corresponding process. This parameter should normally be OFF (0); you should set it ON (1) only when the executive is being debugged. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting BUGCHECKFATAL to ON (1). BUGCHECKFATAL is a DYNAMIC parameter. 2 BUGREBOOT BUGREBOOT enables or disables automatic rebooting of the system if a fatal bugcheck occurs. This parameter should normally be on (1); set it off (0) only when the executive is being debugged. BUGREBOOT is a DYNAMIC parameter. 2 CHANNELCNT CHANNELCNT specifies the maximum number of I/O channels available to processes and to the system. The FILLM quota can be used to reduce the maximum number of I/O channels for a process. A process with a FILLM quota larger than CHANNELCNT is nevertheless limited to the maximum number of I/O channels specified by CHANNELCNT. 2 CLASS_PROT CLASS_PROT performs the nondiscretionary classification checks. CLASS_PROT is also checked by XQP to determine if a classification block should be added to the header of any created files. CLASS_PROT is a DYNAMIC parameter. 2 CLISYMTBL CLISYMTBL sets the size of the command interpreter symbol table, which controls the number of DCL symbols that can be created. CLISYMTBL is a DYNAMIC parameter. 2 CLUSTER_CREDITS CLUSTER_CREDITS specifies the number of per-connection buffers a node allocates to receiving VMS$VAXcluster communications. If the SHOW CLUSTER command displays a high number of credit waits for the VMS$VAXcluster connection, you might consider increasing the value of CLUSTER_CREDITS on the other node. However, in large cluster configurations, setting this value unnecessarily high consumes a large quantity of nonpaged pool. Each receive buffer is at least SCSMAXMSG bytes in size but might be substantially larger depending on the underlying transport. It is not required for all nodes in the cluster to have the same value for CLUSTER_CREDITS. The default value is currently 32. Unless a system has very constrained memory available, VSI recommends that these values not be increased. 2 CONCEAL_DEVICES CONCEAL_DEVICES enables or disables the use of concealed devices. By default, this parameter is set to enable concealed devices (1). This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 CPU_POWER_MGMT_(D) On Integrity servers, a CPU can be placed in "low-power mode" when it is idle. This minimizes power consumption, thereby reducing energy costs for the system. Beginning in Version 8.2- 1, OpenVMS Integrity servers supports this feature based on the settings of two system parameters: CPU_POWER_MGMT and CPU_POWER_ THRSH. A value of 1 for CPU_POWER_MGMT means on (the default); a value of 0 means off. Whenever the CPU_POWER_THRSH parameter value is exceeded, the operating system places an Integrity processor in low-power mode if it is idle. OpenVMS Integrity servers does this only if CPU_POWER_MGMT is on. A CPU returns to normal power when it receives an interrupt. CPU_POWER_MGMT is a DYNAMIC parameter. 2 CPU_POWER_THRSH_(D) On Integrity servers, CPU_POWER_THRSH is a parameter expressed as a percentage. OpenVMS Integrity servers monitors how active each CPU is over a fixed time period. If CPU_POWER_MGMT is on and a CPU is idle for a period of time indicated by CPU_POWER_ THRSH, the CPU is placed in a low-power mode if it is idle. A CPU returns to normal power when it receives an interrupt. For systems supporting real-time operations that require quick response time, VSI recommends that this feature be turned off. Use of this feature can result in a small performance degradation. For more information, see the Intel IA-64 Architecture Software Developer's Manual, Volume 2: IA-64 System Architecture. See also the CPU_POWER_MGMT parameter. CPU_POWER_THRSH is a DYNAMIC parameter. 2 CRD_CONTROL This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. On Alpha and Integrity servers, CRD_CONTROL can be used to expand the function defined by CRDENABLE. CRD_CONTROL is a bit mask for corrected read data (CRD) soft error control flags. These flags control the use of CRDERROR routines. On Alpha and Integrity servers, the following bits are defined: Bit Description 0 Enables CRD processing for all systems. 1 Enables scrubbing (rewriting) of the memory location that induced the CRD. 2 Enables page replacement of the pages that exhibit repeated CRD errors. 3 Forces all memory pages to be included in the PFN database. On systems that contain more than 512 megabytes of memory, all memory is mapped by the PFN database by default. This bit allows the mapping to occur on systems with less than 512 megabytes of memory. 4 Enables extended CRD handling, if available. 5 Enables loading of driver and process for handling server management events. Platform-specific code usually sets this bit if the required hardware and firmware support are available. 6 Disables CRD throttling. 7 Disables System Event Log (SEL) polling. 16-31 Reserved for platform-specific error-handling control. On Alpha and Integrity servers, the default setting is 22, which enables scrubbing, page replacement, and extended CRD handling. 2 CRDENABLE (Alpha and Integrity servers) CRDENABLE enables or disables detection and logging of memory-corrected read data (ECC) errors. This parameter should normally be set to (1). Beginning with OpenVMS Version 7.2, CRD_CONTROL can expand the function of CRDENABLE. (See CRD_CONTROL.) 2 CTLIMGLIM CTLIMGLIM specifies the size of the default image I/O segment; that is channel table and initial buffer pool for image-related file and RMS I/O. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 CTLPAGES CTLPAGES specifies the size of P1 pool. CTLPAGES is automatically changed only when the process logical name table, DCL symbols, or some layered products require an increase in the size of the P1 pool area. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. CTLPAGES is an AUTOGEN parameter. 2 CWCREPRC_ENABLE CWCREPRC_ENABLE controls whether an unprivileged user can create a process on another OpenVMS Cluster node. The default value of 1 allows an unprivileged user to create a detached process with the same UIC on another node. A value of 0 requires that a user have DETACH or CMKRNL privilege to create a process on another node. 2 DBGTK_SCRATCH (Alpha and Integrity servers) DBGTK_SCRATCH specifies how many pages of memory are allocated for the remote debugger. This memory is allocated only if remote debugging is enabled with the 8000 boot flag. Normally, the default value is adequate, but if the remote debugger issues an error message, you should increase this value. See Writing OpenVMS Alpha Device Drivers in C (Margie Sherlock and Lenny S. Szubowicz, Digital Press, 1996). for more information. (This manual has been archived.) 2 DCL_CTLFLAGS DCL_CTLFLAGS is a bit mask that alters default behavior for certain DCL-related functions on a systemwide basis. However, the default values satisfy the needs of most systems. Bits 0 and 2 control the formulation of system-generated process names for processes created using the SPAWN command or LIB$SPAWN library routine. They are provided for compatibility with behavior of prior OpenVMS versions. Note that you can eliminate the use of system-generated names by supplying your own process names. Bit 1 controls the token size used by DCL. Bit 3 controls the maximum number input parameters to command procedure. Bit 4 controls the the maximum length for an user name, for which OpenVMS mail forwarding address is set. DCL_CTLFLAGS bits are described in the following table. Bit Description Bit If clear (the default), the numeric portion of a system- 0 generated spawned process name is generated randomly. If set, the numeric portion is generated sequentially starting with sequence number 1. The option of sequential generation is provided for compatibility with OpenVMS versions prior to Version 7.3-1. However, this choice can be very expensive in performance terms because of the mechanism for finding the next available process name. This mechanism attempts to create all process names beginning with sequence number 1 until it finds one that is unused. Random generation is the preferred choice because it results in a very high probability of finding a unique name on the first try. Bit Controls the token size used by DCL. If clear (the 1 default), this bit instructs DCL to use the traditional token size. A token cannot exceed 255 characters. If this bit is set, extended tokens are used. Extended tokens are 4000 characters. Note that if you turn on extended tokens, file specifications can exceed 255 characters, which might require larger structures for parsing file specifications. Bit If clear (the default), the numeric portion of a system- 2 generated spawned process name has a maximum value of 65535. If set, the numeric portion of the name has a maximum value of 255. The option of a maximum of 255 is provided for compatibility with OpenVMS versions prior to Version 8.3, when it was the only choice. The larger maximum allows many more unique spawned process names for a given process. For this reason, it is the preferred choice. However, the larger maximum uses two additional characters from the process name, which might make it more difficult to identify users uniquely by looking at their spawned process names. If this is an issue on your system, setting bit 2 might be a better choice. Bit If clear (the default), command procedure supports the 3 default eight optional parameters (that is, (P1,P2,...P8)). If set, command procedure supports up to sixteen optional parameters (that is, (P1,P2,...P16)). This is also applicable when using the CALL command to transfer control to a subroutine. Bit This bit controls the the maximum length for an user name, 4 for which OpenVMS mail forwarding address is set. If clear (the default), user name string length is set to a maximum length of 31 characters. If set, user name string length is set to a maximum of 255 characters. Note: Once this bit is set, user name length is set to maximum of 255 characters. Even if this bit is cleared, the behavior remains unchanged, that is, supports user name length of 255 characters, but there is no way to reset it to 31 characters. 2 DEADLOCK_WAIT DEADLOCK_WAIT defines the number of seconds that a lock request must wait before the system initiates a deadlock search on behalf of that lock. Setting DEADLOCK_WAIT to zero disables deadlock checking. Setting DEADLOCK_WAIT to a value greater than zero and less than the default setting provides faster detection of deadlocks but requires more CPU usage. The DEADLOCK_WAIT value is expressed in seconds; therefore, the smallest value you can set is 1 second. Beginning in VSI OpenVMS Version 8.3, a subsecond deadlock wait time, which is set in the system service $SET_PROCESS_PROPERTIESW item code $PPROP$C_ DEADLOCK_WAIT, overrides DEADLOCK_WAIT. For more information, see the $SET_PROCESS_PROPERTIESW system service in VSI OpenVMS System Services Reference Manual. DEADLOCK_WAIT is a DYNAMIC parameter. 2 DEFGID Default POSIX GID used internally by OpenVMS. 2 DEFMBXBUFQUO DEFMBXBUFQUO sets the default for the mailbox buffer quota size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call. DEFMBXBUFQUO is a DYNAMIC parameter. 2 DEFMBXMXMSG DEFMBXMXMSG sets the default for the mailbox maximum message size in bytes when this value is not specified in a Create Mailbox ($CREMBX) system service call. DEFMBXMXMSG is a DYNAMIC parameter. 2 DEFPRI DEFPRI sets the base default priority for processes. DEFPRI is a DYNAMIC parameter. 2 DEFQUEPRI DEFQUEPRI establishes the scheduling priority for jobs entered in batch and output (printer, server, and terminal) queues when no explicit scheduling priority is specified by the submitter. The value of this parameter can range from 0 to 255; the default value is 100. The value of DEFQUEPRI should be less than or equal to MAXQUEPRI. NOTE DEFQUEPRI refers to relative queue scheduling priority, not the execution priority of the job. DEFQUEPRI is a DYNAMIC parameter. 2 DEFUID Default POSIX UID used internally by OpenVMS. 2 DELPRC_EXIT DELPRC_EXIT can be used to control $DELPRC system service options that call exit handlers prior to final cleanup and deletion of a process. The following table describes these options: Option Description 0 Disable the exit handler functionality with $DELPRC. 4 Execute kernel mode exit handlers. 5 (default) Execute exec and more privileged mode exit handlers. 6 Execute supervisor and more privileged mode exit handlers. 7 Execute user and more privileged mode exit handlers. DELPRC_EXIT is a DYNAMIC parameter. 2 DEVICE_NAMING (Alpha and Integrity servers) DEVICE_NAMING is a bit mask indicating whether port allocation classes are used in forming SCSI device names. Following is the bit definition: Bit Definition 0 If 1, enable new naming. 1 Must be 0. This bit is Reserved for use by VSI. 2 If 1, cloned device unit numbers wrap after 9999(not 65472). 3 If 1, cloned device unit numbers wrap after 32767(not 65472). Note that even if both bits are zero, device unit numbers will wrap after 9999 if "nodename$" is prefixed to the name of the device in question (e.g. VMS123$DKA100:); devices whose drivers support larger device numbers will wrap after 65472 (or 32767 if bit 3 is set) only if the nodename is not built into the device name. For more information about port allocation classes, see the VSI OpenVMS Cluster Systems manual. 2 DISABLE_UPCALLS DISABLE_UPCALLS is primarily a debugging aid. It allows the system manager to disable threads upcalls of specific types for the entire system. The value is a bit mask, with the bits corresponding to the upcall types. The upcall types are defined in the definition macro $TMCDEF. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. DISABLE_UPCALLS is a DYNAMIC parameter. 2 DISK_QUORUM The DISK_QUORUM parameter is the name of an optional quorum disk in ASCII. ASCII spaces indicate that no quorum disk is being used. 2 DISMOUMSG DISMOUMSG controls whether the messages that log volume dismounts appear on the operator's terminal and in the operator's log. The default value of 0 disables reporting of these messages. DISMOUMSG is a DYNAMIC parameter. 2 DNVOSI1 DNVOSI1 is reserved to DECnet-Plus for OpenVMS. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 DORMANTWAIT DORMANTWAIT specifies, in seconds, the amount of time that can elapse without a significant event before the system treats a low-priority computable process as a DORMANT process for scheduling purposes. (A low-priority process is a non real-time process whose current priority is equal to or less than the value specified by the system parameter DEFPRI [default=4].) After SUSP (suspended) processes, DORMANT processes are the most likely candidates for memory reclamation by the swapper. Increasing the value of DORMANTWAIT can increase the interval that a low priority process blocks a high priority process if that low priority process is holding a lock or resource that the higher priority process is waiting for. DORMANTWAIT is a DYNAMIC parameter. 2 DR_UNIT_BASE (Alpha only) DR_UNIT_BASE specifies the base value from which unit numbers for DR devices (DIGITAL StorageWorks RAID Array 200 Family logical RAID drives) are counted. DR_UNIT_BASE provides a way for unique RAID device numbers to be generated. DR devices are numbered starting with the value of DR_UNIT_BASE and then counting from there. For example, setting DR_UNIT_BASE to 10 produces device names such as $1$DRA10, $1$DRA11, and so on. Setting DR_UNIT_BASE to appropriate, nonoverlapping values on all cluster members that share the same (nonzero) allocation class ensures that no two RAID devices are given the same name. DR_UNIT_BASE is a GEN parameter. 2 DUMPBUG DUMPBUG enables (1) or disables (0) the writing of error log buffers and memory contents to SYS$SYSTEM:SYSDUMP.DMP when a fatal bugcheck occurs. This parameter should be off (0) only when the executive is being debugged. 2 DUMPSTYLE DUMPSTYLE specifies the method of writing system dumps. DUMPSTYLE is a 32-bit mask, with the following bits defined. Each bit can be set independently. The value of the system parameter is the sum of the values of the bits that have been set. Remaining or undefined values are reserved for VSI use only. Bit Mask Description 0 00000001 0 = Full dump (SYSGEN default). The entire contents of physical memory are written to the dump file. 1 = Selective dump. The contents of memory are written to the dump file selectively to maximize the usefulness of the dump file while conserving disk space. 1 00000002 0 = Minimal console output. 1 = Full console output (includes stack dump, register contents, and so on). 2 00000004 0 = Dump to system disk. 1 = Dump off system disk (DOSD) to an alternate disk. (see the VSI OpenVMS System Manager's Manual for details.) 3 (Alpha and 00000008 0 = Do not compress. Integrity servers) 1 = Compress. (VAX systems do not support dump compression.) 4 (Alpha and 00000010 0 = Dump shared memory. Integrity servers) 1 = Do not dump shared memory. (VAX systems do not support shared memory.) 5 - 14 reserved for VSI use only. 15 (VAX only) 00008000 0 = Disable use of bits 16 - 27. (Specific to VAX 7000s.) 1 = Enable use of bits 16 - 27. 16 - 27 (VAX 0FFF0000 Range of DOSD unit numbers. (VAX only) systems do not support shared memory.) 28 - 31 reserved for VSI use only. If you plan to enable the Volume Shadowing minimerge feature on an Alpha or Integrity servers disk, be sure to specify DOSD to an alternate disk. NOTE On Alpha and Integrity servers, you can save space on the system disk and, in the event of a crash, save time recording the system memory, by using the OpenVMS Alpha and Integrity servers dump compression feature. Unless you override the default AUTOGEN calculations (by setting DUMPSTYLE in MODPARAMS.DAT), AUTOGEN uses the following algorithm: o On a system with less than 128 MB of memory, the system sets the DUMPSTYLE to 1 (a raw selective dump) and sizes the dump file appropriately. o On a system with 128 MB of memory or greater, the system sets the DUMPSTYLE to 9 (a compressed selective dump), and creates the dump file at two-thirds the value of the corresponding raw dump. Examples: The mask of 00000006 directs the system to send a full dump, with full console output, off the system disk (to the alternate disk). For a VAX 7000, a mask of 00098006 directs the system to send a full dump with full console output to the DOSD whose unit number is 9. On Alpha and Integrity servers, the mask of 00000009 directs the system to compress a selective dump with minimal console output. DUMPSTYLE has AUTOGEN and DYNAMIC attributes. 2 ERLBUFFERPAG_S2 ERLBUFFERPAG_S2 specifies the amount of S2 space memory to allocate for each S2 space error log buffer requested by the ERRORLOGBUFF_S2 parameter. If you increase ERLBUFFERPAG_S2, you must either run AUTOGEN or manually increase the size of both the system dump file and the error log dump file. ERLBUFFERPAG_S2 is an AUTOGEN parameter on Alpha and Integrity servers. 2 ERLBUFFERPAGES ERLBUFFERPAGES specifies the amount of S0 space memory to allocate for each S0 space error log buffer requested by the ERRORLOGBUFFERS parameter. ERLBUFFERPAGES is an AUTOGEN parameter on Alpha and Integrity servers. 2 ERRORLOGBUFF_S2 ERRORLOGBUFF_S2 specifies the number of S2 space error log buffers reserved for system error log entries. Each buffer is ERLBUFFERPAG_S2 in length. If ERRORLOGBUFF_S2 is too low, messages might not be written to the error log file. If it is too high, the buffers can consume unnecessary physical pages. If you increase ERRORLOGBUFF_S2, you must either run AUTOGEN or manually increase the size of both the system dump file and the error log dump file. ERRORLOGBUFF_S2 is an AUTOGEN parameter on Alpha and Integrity servers. 2 ERRORLOGBUFFERS ERRORLOGBUFFERS specifies the number of S0 space error log buffers reserved for system error log entries. Each buffer is ERLBUFFERPAGES in length. If ERRORLOGBUFFERS is too low, messages might not be written to the error log file. If it is too high, the buffers can consume unnecessary physical pages. ERRORLOGBUFFERS is an AUTOGEN parameter on Alpha and Integrity servers. 2 EXECSTACKPAGES (Alpha and Integrity servers) EXECSTACKPAGES controls the number of pages allocated for each RMS exec stack. EXECSTACKPAGES is a DYNAMIC parameter. 2 EXPECTED_VOTES EXPECTED_VOTES specifies the maximum number of votes that can be present in a cluster at any given time. Set it to a value that is equal to the sum of the vote parameters of all cluster members, plus any votes that are contributed by the quorum disk. This value is used to automatically derive the number of votes that must be present for the cluster to function (quorum). EXPECTED_VOTES is an AUTOGEN attribute parameter. 2 EXTRACPU EXTRACPU sets the time, in units of 10 ms, allotted to each of a process's exit handlers (for each access mode) after the process times out (that is, reaches its CPU time limit). EXTRACPU is a DYNAMIC attribute parameter. 2 FAST_PATH (Alpha and Integrity servers) FAST_PATH is a static system parameter that enables (1) or disables (0) the Fast Path performance features for all Fast Path-capable ports. Starting in OpenVMS Version 7.2, FAST_PATH is enabled by default. In Versions 7.0 and 7.1, FAST_PATH was disabled by default. For additional information, see FAST_PATH_PORTS. 2 FAST_PATH_PORTS (Alpha and Integrity servers) FAST_PATH_PORTS is a static parameter that deactivates Fast Path for specific drivers. FAST_PATH_PORTS is a 32-bit mask, with a bit assigned for each Fast Path port driver. The following table describes the bit values: Bit Value Description 1 Indicates that Fast Path is disabled for ports serviced by the corresponding driver. 0 Indicates that Fast Path is not disabled for ports serviced by the corresponding driver. Beginning in OpenVMS Version 7.3-1, values of specific bit positions are those described in the following table: Bit Position Description 0 Controls Fast Path for PKQDRIVER (for parallel SCSI). 1 Controls Fast Path for FGEDRIVER (for Emulex LP7000, LP8000, LP9002, LP9802, LP10000 FibreChannel). 2 Controls Fast Path for PKADRIVER (for Adaptec AIC-78xx Ultra3 SCSI). 3 Controls Fast Path for PEDRIVER (for LAN). 4 Controls Fast Path for PKRDRIVER (for SMART Array 5300). 5 Controls Fast Path for PKMDRIVER, the LSI Logic LSI53C1030 SCSI port driver. 6 Controls Fast Path for PGQDRIVER, the Qlogic ISP23xx FibreChannel port driver. Currently, the default setting for FAST_PATH_PORTS is 0, which means that Fast Path is enabled for all drivers that appear in the table. In addition, note the following: o CI drivers are not controlled by FAST_PATH_PORTS. Fast Path for CI is enabled and disabled exclusively by the FAST_PATH system parameter. o FAST_PATH_PORTS is relevant only if the FAST_PATH system parameter is enabled (equal to 1). Setting FAST_PATH to zero has the same effect as setting all the bits in FAST_PATH_PORTS to 1. For additional information, see FAST_PATH. For an explanation of how to set the bits, see the OpenVMS I/O User's Reference Manual. 2 FREEGOAL FREEGOAL establishes the number of pages that you want to reestablish on the free-page list following a system memory shortage. Memory shortages occur when the system drops below the minimum number of pages required on the free-page list (FREELIM). The value of FREEGOAL must always be greater than or equal to the value of FREELIM. FREEGOAL has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 FREELIM FREELIM sets the minimum number of pages that must be on the free-page list. The system writes pages from the modified-page list, swaps out working sets, or reduces the size of the working sets to maintain the minimum count. While the larger free-page list generally means less page I/O, it also means less space for the balance set, which tends to result in more swap I/O. You can monitor the size of the free-page list, the amount of page, and the amount of swap with the MONITOR IO command of the Monitor utility. FREELIM has the AUTOGEN and MAJOR attributes. 2 GALAXY (Alpha Galaxy platforms only) The GALAXY parameter sets memory sharing. Specify one of the following: Value Description 0 The default. Do not participate in a memory sharing. 1 Participate in a memory sharing. When you set GALAXY to 1 in a hard partition, OpenVMS instances will share memory between soft partitions within that hard partition. (You can run more than two soft partitions in a hard partition, and you might might not want to share memory among all of them.) Note that GALAXY specifies only if a node uses shared memory. You do not need to use the parameter to run multiple cooperative instances of OpenVMS; you do this by console setup of the configuration tree that you want. 2 GBLPAGES GBLPAGES sets the number of global page table entries allocated at bootstrap time. Each global section requires 1 global page table entry per section page, plus 2 entries, with the total rounded up to an even number. Users with CMKRNL privilege can change this parameter on a running system. Increasing the value of this parameter allows the global page table to expand, on demand, up to the maximum size. The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility (INSTALL) and reduce the value of GBLPAGES accordingly. However, do not set the value of this parameter too low, because the page table entries use little permanently resident memory. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter. GBLPAGES has the AUTOGEN, DYNAMIC, FEEDBACK, GEN, and MAJOR attributes. 2 GBLPAGFIL GBLPAGFIL defines the maximum number of systemwide pages allowed for global page-file sections (scratch global sections that can be used without being mapped to a file). These global page- file sections can be temporary, permanent, system, or group, and are allocated from the page file specified in the system process header at bootstrap time. When you allow pages for global page-file sections, you must increase the size of the page file accordingly. Users with CMKRNL privilege can change this parameter value on a running system. Global page-file sections are created with the Create and Map Section system services ($CREATE_GPFILE, $CRMPSC, and $CRMPSC_ GPFILE_64) without an explicit disk file. These sections are used for the RMS global buffers required for shared files. Users of shared files should note that global page-file sections cause both the global page table and the default system page file (PAGEFILE.SYS) to be used. If the value of GBLPAGFIL is too small, $CRMPSC issues an error message when you attempt to create global page-file sections. You must have scratch global sections if you use RMS global buffers. Each file using global buffers requires, in the system page file, the file's bucket size multiplied by the number of global buffers for that file. If the file's bucket size varies, as with RMS indexed files, use the maximum bucket size. For shared sequential files, use the multiblock count of the first stream to perform the $CONNECT service in place of the file's bucket size. The default value for this parameter is adequate for most systems. However, if your site uses RMS global buffering to a significant extent, you may need to raise the value of GBLPAGFIL. Use the /GLOBAL qualifier of the Install utility to examine the number of pages consumed by RMS global buffers. The global sections used by RMS for global buffers have the prefix RMS$ followed by 8 hexadecimal digits. Global buffers are enabled with the DCL command SET FILE/GLOBAL_BUFFERS, which is described in the VSI OpenVMS DCL Dictionary. GBLPAGFIL is an AUTOGEN-altered and a DYNAMIC parameter. 2 GBLSECTIONS GBLSECTIONS sets the number of global section descriptors allocated in the system header at bootstrap time. Each global section requires one descriptor. Each descriptor takes 32 bytes of permanently resident memory. The default value is sufficient for the images normally installed as shared in the system startup command procedures. Once the system is running and all global sections are created, you can examine the actual requirements with the /GLOBAL qualifier of the Install utility and reduce the value of GBLSECTIONS accordingly. However, the value of this parameter should not be set too low. If you plan to install many user images as shared, or if user programs are likely to create many global sections, you must increase the value of this parameter. If the value of GBLSECTIONS is too small, you receive a message from the Install utility at system startup time or whenever you install images manually. Note that too large a value for GBLSECTIONS wastes physical memory. GBLSECTIONS has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 GB_CACHEALLMAX (Alpha and Integrity servers) If a file is connected to RMS with the RMS global buffer DEFAULT option enabled, the number of of blocks cached is either a maximum of the GB_CACHEALLMAX parameter or a percentage of the file, whichever results in a larger global count. Note that although a maximum cache size of %x7FFFFFFF is supported for an indexed file, sequential and relative file organizations are restricted to a maximum cache size of 32767. GB_CACHEALLMAX is a DYNAMIC parameter. 2 GB_DEFPERCENT (Alpha and Integrity servers) If a file is connected to RMS with the RMS global buffer DEFAULT option enabled, either a percentage (GB_DEFPERCENT) of the file is cached or up to GB_CACHEALLMAX blocks of it are cached, whichever results in a larger global buffer count. A percentage greater than 100 percent can be specified for GB_DEFPERCENT to provide growing room for a file in the global cache. Note that although a maximum cache size of %x7FFFFFFF is supported for an indexed file, sequential and relative file organizations are restricted to a maximum cache size of 32767. GB_DEFPERCENT is a DYNAMIC parameter. 2 GH_EXEC_CODE (Alpha and Integrity servers) GH_EXEC_CODE specifies the size in pages of the execlet code granularity hint region. GH_EXEC_CODE has the AUTOGEN and FEEDBACK attributes. 2 GH_EXEC_DATA (Alpha and Integrity servers) GH_EXEC_DATA specifies the size in pages of the execlet data granularity hint region. GH_EXEC_DATA has the AUTOGEN and FEEDBACK parameters. 2 GH_RES_CODE (Alpha and Integrity servers) GH_RES_CODE specifies the size in pages of the resident image code granularity hint region. GH_RES_CODE has the AUTOGEN and FEEDBACK attributes. 2 GH_RES_CODE_S2 Specifies the size in pages of the resident 64-bit S2 space resident image code granularity hint region. 2 GH_RES_DATA (Alpha and Integrity servers) GH_RES_DATA specifies the size in pages of the resident image data granularity hint region. If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image LDR$WRAPUP releases all unused pages in the granularity hint region at the the end of system startup. The unused pages of the resident image granularity hint region are either reserved for future use, or given back to the free memory list. GH_RES_DATA has the AUTOGEN and FEEDBACK attributes. 2 GH_RSRVPGCNT GH_RSRVPGCNT specifies the number of pages in the resident image code granularity hint region that the Install utility can use after the system has finished booting. If bit 2 of the LOAD_SYS_IMAGES parameter is set, the image LDR$WRAPUP releases all unused pages in the granularity hint region at the the end of system startup. The unused pages of the resident image granularity hint region are either reserved for future use, or given back to the free memory list. GH_RSRVPGCNT specifies the number of pages that LDR$WRAPUP attempts to leave in the resident image code granularity hint region. If the GH_RSRVPGCNT number of pages is larger than the unused pages in the granularity hint region, the region is not expanded to accommodate the number of pages requested. GH_RSRVPGCNT is a FEEDBACK attribute parameter. 2 GLX_INST_TMO (Alpha Galaxy platforms only) GLX_INST_TMO is the time (in milliseconds) that an instance in a Galaxy sharing set can fail to increment its timeout value before the other sharing instances presume that the instance failed and remove it from the sharing set. The default is 20,000 ms (20 seconds). 2 GLX_SHM_REG For Alpha Galaxy systems, GLX_SHM_REG is the number of shared memory region structures configured into the Galaxy Management Database (GMDB). If set to 0, the default number of shared memory regions are configured. If the condition value SS$_INSF_SHM_REG is returned for the $CRNMPSC_GDZRO_64 system service with the flag SEC$M_SHM_REG, the Galaxy shared memory code has run out of internal SHM_REG data structures. You need to increase the system parameter GLX_SHM_REG and reboot all Galaxy instances with this larger parameter value. 2 GROWLIM GROWLIM sets the number of pages that the system must have on the free-page list so that a process can add a page to its working set when it is above quota. GROWLIM has no effect if the process is below its working set quota. GROWLIM acts as a fast shutoff to the working set extent mechanism based on the system's free memory. GROWLIM has AUTOGEN, DYNAMIC, and MAJOR attributes. 2 IEEE_ADDRESS IEEE_ADDRESS is reserved for VSI use only. 2 IEEE_ADDRESSH IEEE_ADDRESSH is reserved for VSI use only. 2 IJOBLIM IJOBLIM sets the maximum number of interactive jobs that can be on the system concurrently. You can control the maximum number of concurrent interactive users on the system with the DCL command SET LOGINS/INTERACTIVE. IJOBLIM is a DYNAMIC parameter. 2 IMGIOCNT IMGIOCNT specifies the default number of pages of image I/O address space to be allocated for the image activator if not specified at program link time. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 IMGREG_PAGES (Alpha and Integrity servers) IMGREG_PAGES is the number of pages to reserve in P1 space for images to be installed with shareable address data. If IMGREG_PAGES is set to 0, no images are installed with shared address data. The default is 10,000 pages. For more information, see the INSTALL section in the VSI OpenVMS System Management Utilities Reference Manual. 2 IO_PRCPU_BITMAP (Alpha and Integrity servers) This parameter is a bitmap representing up to 1024 CPUs. Each bit set in this bitmap indicates that the corresponding CPU is available for use as a Fast Path preferred CPU. IO_PRCPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023 are all enabled for Fast Path port assignment.) You might want to disable the primary CPU from serving as a preferred CPU by leaving its bit clear in IO_PRCPU_BITMAP, which reserves the primary CPU for non-Fast Path IO operations to use. To change the value of IO_PRCPU_BITMAP in SYSBOOT or SYSGEN, specify a list of individual bits or contiguous groups of bits. For example: SYSGEN> SET IO_PRCPU_BITMAP 0,5,17-21 This command sets bits 0, 5, 17, 18, 19, 20, and 21 in the bitmap and clears all other bits. Changing the value of IO_PRCPU_BITMAP causes the FASTPATH_SERVER process to run the automatic assignment algorithm that spreads Fast Path ports evenly among the new set of usable CPUs. For additional information, see FAST_PATH and FAST_PATH_PORTS. This parameter replaces IO_PREFER_CPU. 2 IOTA IOTA specifies the amount of time (in 10-millisecond units) to charge to the current residence quantum for each voluntary wait. The correct value approximates the cost of a disk I/O neglecting wait time. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 IRPCOUNT IRPCOUNT sets the number of preallocated intermediate request packets. Each packet requires 160 bytes of permanently resident memory. If IRPCOUNT is too large, physical memory is wasted. If IRPCOUNT is too small, the system increases its value automatically, as needed, to permit proper performance. However, the system cannot increase IRPCOUNT beyond the value of IRPCOUNTV. Allowing this growth causes a physical memory penalty. If IRPCOUNT is underconfigured, the penalty is 4 percent of physical memory from the configured value to the actual value on the running system. You can use the DCL command SHOW MEMORY/POOL/FULL to determine IRPCOUNT usage. IRPCOUNT has the GEN and MAJOR attributes. 2 IRPCOUNTV IRPCOUNTV establishes the upper limit to which IRPCOUNT can be automatically increased by the system. If this parameter is set too low, system performance can be adversely affected because IRPCOUNTV cannot be used for nonpaged pool requests. A physical memory penalty of 1 percent results for any unused growth space (1 longword for every 3 unused intermediate request packets). IRPCOUNTV has the GEN attribute. 2 JBOBLIM This parameter is no longer in use. 2 JOBCTLD System managers do not usually alter JOBCTLD; this word of debug flags is used in rolling upgrades of OpenVMS. If bit 0 is set, the queue manager does not start. The default is 0. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 KSTACKPAGES (Alpha and Integrity servers) KSTACKPAGES controls the number of pages allocated for process kernel stacks. 2 LAN_FLAGS (Alpha and Integrity servers) LAN_FLAGS is a bit mask used to enable features in the local area networks port drivers and support code. The default value for LAN_FLAGS is 0. The bit definitions are as follows: Bit Description 0 The default of zero indicates that ATM devices run in SONET mode. If set to 1, this bit indicates ATM devices run in SDH mode. 1 If set, this bit enables a subset of the ATM trace and debug messages in the LAN port drivers and support code. 2 If set, this bit enables all ATM trace and debug messages in the LAN port drivers and support code. 3 If set, this bit runs UNI 3.0 over all ATM adapters. (Auto-sensing of the ATM UNI version is enabled if both bit 3 and bit 4 are off (0).) 4 If set, this bit runs UNI 3.1 over all ATM adapters. (Auto-sensing of the ATM UNI version is enabled if both bit 3 and bit 4 are off (0).) 5 If set, disables auto-negotiation over all Gigabit Ethernet Adapters. 6 If set, enables the use of jumbo frames over all Gigabit Ethernet Adapters. 7 Reserved. 8 If set, disables the use of flow control over all LAN adapters that support flow control. 9 Reserved. 10 Reserved. 11 If set, disables the logging of error log entries by LAN drivers. 12 If set, enables a fast timeout on transmit requests, usually between 1 and 1.2 seconds instead of 3 to 4 seconds, for most LAN drivers. 13 If set, transmits that are given to the LAN device and never completed by the device (transmit timeout condition) are completed with error status (SS$_ABORT) rather than success status (SS$_NORMAL). LAN_FLAGS is a DYNAMIC parameter. 2 LCKMGR_CPUID (Alpha and Integrity servers) LCKMGR_CPUID controls the CPU that the Dedicated CPU Lock Manager runs on. This is the CPU that the LCKMGR_SERVER process utilizes if you turn this feature on with the LCKMGR_MODE system parameter. If the specified CPU ID is either the primary CPU or a nonexistent CPU, the LCKMGR_SERVER process utilizes the lowest nonprimary CPU. For more information, see the LCKMGR_MODE system parameter. LCKMGR_CPUID is a DYNAMIC parameter. 2 LCKMGR_MODE (Alpha and Integrity servers) The LCKMGR_MODE parameter controls use of the Dedicated CPU Lock Manager. Setting LCKMGR_MODE to a number greater than zero (0) indicates the number of CPUs that must be active before the Dedicated CPU Lock Manager is turned on. The Dedicated CPU Lock Manager performs all locking operations on a single dedicated CPU. This can improve system performance on large SMP systems with high MP_Synch associated with the lock manager. If the number of active CPUs is greater than or equal to LCKMGR_ MODE, a LCKMGR_SERVER process is created to service locking operations. This process runs at a real-time priority of 63 and is always current. In addition, if the number of active CPUs should ever be reduced below the required threshold by either a STOP/CPU command or by a CPU reassignment in a Galaxy configuration, the Dedicated CPU Lock Manager automatically turns off within one second, and the LCKMGR_SERVER is placed in a hibernate state. If the number of active CPUs is increased, the LCKMGR_SERVER resumes servicing locking operations. Specify one of the following: o Zero (0) indicates that the Dedicated CPU Lock Manager is off (the default). o A number greater than zero (0) indicates the number of CPUs that must be active before the Dedicated CPU Lock Manager will turn on. When the Dedicated CPU Lock Manager is turned on, fast path devices are not assigned to the CPU used by the Dedicated CPU Lock Manager. When the Dedicated CPU Lock Manager is turned on, fast path devices are not assigned to the CPU used by the Dedicated CPU Lock Manager. For more information about use of the Dedicated CPU Lock Manager, see the OpenVMS Performance Management manual. LCKMGR_MODE is a DYNAMIC parameter. 2 LGI_BRK_DISUSER LGI_BRK_DISUSER turns on the DISUSER flag in the UAF record when an attempted break-in is detected, thus permanently locking out that account. The parameter is off (0) by default. You should set the parameter (1) only under extreme security watch conditions, because it results in severely restricted user service. LGI_BRK_DISUSER is a DYNAMIC parameter. 2 LGI_BRK_LIM LGI_BRK_LIM specifies the number of failures that can occur at login time before the system takes action against a possible break-in. The count of failures applies independently to login attempts by each user name, terminal, and node. Whenever login attempts from any of these sources reach the break-in limit specified by LGI_BRK_LIM, the system assumes it is under attack and initiates evasive action as specified by the LGI_HID_TIM parameter. The minimum value is 1. The default value is usually adequate. LGI_BRK_LIM is a DYNAMIC parameter. 2 LGI_BRK_TERM LGI_BRK_TERM causes the terminal name to be part of the association string for the terminal mode of break-in detection. When LGI_BRK_TERM is set to off (0), the processing considers the local or remote source of the attempt, allowing break-in detection to correlate failed access attempts across multiple terminal devices. When set to on (1), LGI_BRK_TERM assumes that only local hard-wired or dedicated terminals are in use and causes breakin detection processing to include the specific local terminal name when examining and correlating break-in attempts. Ordinarily, LGI_BRK_TERM should be set to off (0) when physical terminal names are created dynamically, such as when network protocols like LAT and Telnet are in use. LGI_BRK_TERM is a DYNAMIC parameter. 2 LGI_BRK_TMO LGI_BRK_TMO specifies the length of the failure monitoring period. This time increment is added to the suspect's expiration time each time a login failure occurs. Once the expiration period passes, prior failures are discarded, and the suspect is given a clean slate. LGI_BRK_TMO is a DYNAMIC parameter. 2 LGI_CALLOUTS LGI_CALLOUTS specifies the number of installation security policy callout modules to be invoked at each login. LGI_CALLOUTS must be set to 0 unless callout modules are present. LGI_CALLOUTS is a DYNAMIC parameter. 2 LGI_HID_TIM LGI_HID_TIM specifies the number of seconds that evasive action persists following the detection of a possible break-in attempt. The system refuses to allow any logins during this period, even if a valid user name and password are specified. LGI_HID_TIM is a DYNAMIC parameter. 2 LGI_PWD_TMO LGI_PWD_TMO specifies, in seconds, the period of time a user has to enter the correct system password (if used). LGI_PWD_TMO also establishes the timeout period for users to enter their personal account passwords at login time. Also, when using the SET PASSWORD command, LGI_PWD_TMO specifies the period of time the system waits for a user to type in a new password, an old password, and the password verification. LGI_PWD_TMO is a DYNAMIC parameter. 2 LGI_RETRY_LIM LGI_RETRY_LIM specifies the number of retry attempts allowed users attempting to log in. If this parameter is greater than 0, and a legitimate user fails to log in correctly because of typing errors, the user does not automatically lose the carrier. Instead (provided that LGI_RETRY_TMO has not elapsed), by pressing the Return key, the user is prompted to enter the user name and password again. Once the specified number of attempts has been made without success, the user loses the carrier. As long as neither LGI_BRK_LIM nor LGI_BRK_TMO has elapsed, the user can dial in again and reattempt login. LGI_RETRY_LIM is a DYNAMIC parameter. 2 LGI_RETRY_TMO LGI_RETRY_TMO specifies the number of seconds allowed between login retry attempts after each login failure. (Users can initiate login retries by pressing the Return key.) This parameter is intended to be used with the LGI_RETRY_LIM parameter; it allows dialup users a reasonable amount of time and number of opportunities to attempt logins before they lose the carrier. LGI_RETRY_TMO is a DYNAMIC parameter. 2 LNMPHASHTBL LNMPHASHTBL sets the size of the process logical name hash table. Logical names are hashed using a function of the name length and contents. The LNMPHASHTBL parameter determines the number of entries for process-private logical names. The recommended setting is the average number of process-private logical names. Note that the hashed values are rounded up to the nearest power of 2. LNMPHASHTBL has the GEN attribute. On VAX systems, LNMPHASHTBL is also an AUTOGEN-altered parameter. 2 LNMSHASHTBL LNMSHASHTBL sets the size of the system logical name hash table. Logical names are hashed using a function of the name length and contents. The LNMSHASHTBL parameter determines the number of entries for shareable logical names. These names include all names from the system, group, and job logical name tables. The recommended setting allows one to four logical names per hash table entry. The default setting is usually adequate, unless your installation has a large number of groups, or many jobs are active simultaneously. In that case, an increase in the value of the next higher power of 2 might improve logical name translation performance. Note that the hashed values are rounded up to the nearest power of 2. LNMSHASHTBL has the AUTOGEN, FEEDBACK, and GEN attributes. 2 LOAD_PWD_POLICY LOAD_PWD_POLICY controls whether the SET PASSWORD command attempts to use site-specific password policy routines, which are contained in the shareable image SYS$LIBRARY:VMS$PASSWORD_ POLICY.EXE. The default is 0, which indicates not to use policy routines. 2 LOAD_SYS_IMAGES This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. LOAD_SYS_IMAGES controls the loading of system images described in the system image data file, VMS$SYSTEM_IMAGES. This parameter is a bit mask. On Alpha and Integrity servers, the following bits are defined: Bit Description 0 (SGN$V_LOAD_SYS_IMAGES) Enables loading alternate execlets specified in VMS$SYSTEM_IMAGES.DATA. 1 (SGN$V_EXEC_SLICING) Enables executive slicing. 2 (SGN$V_RELEASE_PFNS) Enables releasing unused portions of the Alpha and Integrity servers huge pages. These bits are on by default. Using conversational bootstrap exec slicing can be disabled. On Alpha and Integrity servers, LOAD_SYS_IMAGES is an AUTOGEN parameter. 2 LOCKDIRWT LOCKDIRWT determines the portion of lock manager directory that this system handles. The default value is usually adequate. LOCKDIRWT is an AUTOGEN parameter. 2 LOCKIDTBL LOCKIDTBL sets the initial number of entries in the system Lock ID table and defines the amount by which the Lock ID table is extended whenever the system runs out of locks. One entry must exist for each lock in the system; each entry requires 4 bytes. For simple timesharing systems, the default value is adequate. If your application uses many locks, as in the case of heavy RMS file sharing or a database management application, you should increase this parameter. When you change the value of LOCKIDTBL, examine the value of RESHASHTBL and change it if necessary. The OpenVMS Lock Management facility is described in the VSI OpenVMS Programming Concepts Manual. You can monitor locks with the MONITOR LOCK command of the Monitor utility. LOCKIDTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes. 2 LOCKIDTBL_MAX LOCKIDTBL_MAX is obsolete beginning with OpenVMS Version 7.1. 2 LOCKRETRY LOCKRETRY establishes the number of attempts made to lock a multiprocessor data structure. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 LOCKRMWT NOTE On OpenVMS Version 8.3 systems, LOCKRMWT does not control lock remastering. See LOCKDIRWT. LOCKRMWT can have a value from zero to 10. The default is 5. Remaster decisions are based on the difference in lock remaster weights between the master and a remote node. When weights are equal, the remote node needs about 13% more activity before the tree is remastered. If a remote node has a higher lock remaster weight, the amount of activity is less. If the remote node has a lower lock remaster weight, the additional activity required to move the tree is much greater. Lock remaster weights of zero and 10 have additional meanings. A value of zero indicates that a node does not want to master trees and always remasters to an interested node with a higher LOCKRMWT. Lock trees on an interested node with a LOCKRMWT lower than 10 are remastered to the node with a weight of 10 for LOCKRMWT. LOCKRMWT is a DYNAMIC parameter. 2 LONGWAIT LONGWAIT defines how much real time (in seconds) must elapse before the swapper considers a process to be temporarily idle. This parameter is applied to local event flag (LEF) and hibernate (HIB) waits to detect such conditions as an inactive terminal or ACP. LONGWAIT has the DYNAMIC, GEN, and MAJOR attributes. On Alpha and Integrity servers, LONGWAIT is also an AUTOGEN-altered parameter. 2 MAXBOBMEM (Alpha and Integrity servers) MAXBOBMEM defines the maximum amount of physical memory, measured in pagelets, that can be associated with a single buffer object created by a process in user mode. The default value of 0 means there is no system- imposed limit on the size of a buffer object. MAXBOBMEM is a DYNAMIC parameter. Other MAXBOB* parameters are obsolete beginning with OpenVMS Version 7.3. 2 MAXBUF MAXBUF sets the maximum allowable size for any single buffered I/O packet. Buffered I/O packets are allocated from the permanently resident nonpaged dynamic pool. The terminal, mailbox, and printer device drivers are examples of device drivers that perform buffered I/O. The number of bytes specified in the I/O request plus the size of a driver-dependent and function-dependent header area determine the required buffered I/O packet size. The size of the header area is a minimum of 16 bytes; there is no absolute upper limit. However, this header area is usually a few hundred bytes in size. The default value on Alpha and Integrity servers continues to be 8192. The maximum value of MAXBUF is 64000 bytes. MAXBUF is a DYNAMIC parameter. 2 MAXCLASSPRI If class scheduling is enabled, MAXCLASSPRI sets the maximum range in the priority range of class-scheduled processes. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. MAXCLASSPRI is a DYNAMIC parameter. 2 MAXPROCESSCNT MAXPROCESSCNT sets the number of process entry slots allocated at bootstrap time. One slot is required for each concurrent process on the system. Each slot requires 6 bytes of permanently resident memory. The default value is normally configured to allow you to create the desired number of processes. If the following message appears, you need to increase the value of MAXPROCESSCNT: %SYSTEM-F-NOSLOT, No PCB to create process On Alpha and Integrity servers beginning with Version 8.1, the default value is 32,767. MAXPROCESSCNT has the AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 MAXQUEPRI MAXQUEPRI determines the highest scheduling priority that can be assigned to jobs entered in batch and output (printer, server, and terminal) queues without the submitter process having OPER or ALTPRI privilege. The value of this parameter can range from 0 to 255; the default is 100. The value of MAXQUEPRI should be greater than or equal to DEFQUEPRI. NOTE MAXQUEPRI refers to relative queue scheduling priority, not to the execution priority of the job. MAXQUEPRI is a DYNAMIC parameter. 2 MAXSYSGROUP MAXSYSGROUP sets the highest value that a group number can have and still be classified as a system UIC group number. Note that the specification is not in octal unless preceded by the %O radix indicator. This parameter is normally left at 8 (10 octal). MAXSYSGROUP is a DYNAMIC parameter. 2 MC_SERVICES_P0 (Alpha only) MC_SERVICES_P0 controls whether other MEMORY CHANNEL nodes in the cluster continue to run if this node bugchecks or shuts down. A value of 1 causes other nodes in the MEMORY CHANNEL cluster to crash with bugcheck code MC_FORCED_CRASH if this node bugchecks or shuts down. The default value is 0. A setting of 1 is intended only for debugging purposes; the parameter should otherwise be left at its default value. MC_SERVICES_P0 is a DYNAMIC parameter. 2 MC_SERVICES_P1 (Alpha only) This special parameter is reserved for VSI use. Its value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P1 is a DYNAMIC parameter. 2 MC_SERVICES_P2 (Alpha only) MC_SERVICES_P2 specifies whether to load the PMDRIVER (PMA0) MEMORY CHANNEL cluster port driver. PMDRIVER is a driver that serves as the MEMORY CHANNEL cluster port driver. It works together with MCDRIVER (the MEMORY CHANNEL device driver and driver interface) to provide MEMORY CHANNEL clustering. If PMDRIVER is not loaded, cluster connections are not made over the MEMORY CHANNEL interconnect. The default value is 1, which causes PMDRIVER to be loaded when you boot the system. When you run CLUSTER_CONFIG.COM and select the MEMORY CHANNEL option, PMDRIVER is loaded automatically when you reboot the system. VSI recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P3 (Alpha only) MC_SERVICES_P3 specifies the maximum number of tags supported. The maximum value is 2048, and the minimum value is 100. The default value is 800. VSI recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P3 is a DYNAMIC parameter. 2 MC_SERVICES_P4 (Alpha only) MC_SERVICES_P4 specifies the maximum number of regions supported. The maximum value is 4096, and the minimum value is 100. The default value is 200. VSI recommends that this value not be changed. This parameter value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P5 (Alpha only) MC_SERVICES_P5 is reserved for VSI use only and must remain at the default value of 8000000. This value must be the same on all nodes connected by MEMORY CHANNEL. MC_SERVICES_P5 is a DYNAMIC parameter. 2 MC_SERVICES_P6 (Alpha only) MC_SERVICES_P6 specifies MEMORY CHANNEL message size, the body of an entry in a free queue, or a work queue. The maximum value is 65536, and the minimum value is 544. The default value is 992. This value is suitable in all cases except for systems with highly constrained memory. For such systems, you can reduce the memory consumptions of MEMORY CHANNEL by slightly reducing the default value of 992. The value of MC_ SERVICES_P6 must always be equal to or greater than the result of the following calculations: 1. Select the larger of SCS_MAXMSG and SCS_MAXDG. 2. Round that value up to the next quadword. The value of MC_SERVICES_P6 must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P7 (Alpha only) MC_SERVICES_P7 specifies whether to suppress or display messages about MEMORY CHANNEL activities on this node. This parameter can be set to a value of 0, 1, or 2: o A value of 0 indicates nonverbose mode: no informational messages appear on the console or in the error log. o A value of 1 indicates verbose mode: informational messages from both MCDRIVER and PMDRIVER appear on the console and in the error log. o A value of 2 provides the same output as a value of 1, with the addition of PMDRIVER stalling and recovery messages. The default value is 0. VSI recommends that this value not be changed except while debugging MEMORY CHANNEL problems or adjusting the MC_SERVICES_P9 parameter. MC_SERVICES_P7 is a DYNAMIC parameter. 2 MC_SERVICES_P8 (Alpha only) MC_SERVICES_P8 is reserved for VSI use only and must remain at the default value of 0. The value must be the same on all nodes connected by MEMORY CHANNEL. 2 MC_SERVICES_P9 (Alpha only) MC_SERVICES_P9 specifies the number of initial entries in a single channel's free queue. The maximum value is 2048, and the minimum value is 10. Note that MC_SERVICES_P9 is not a dynamic parameter; you must reboot the system after each change for that change to take effect. The default value is 150. VSI recommends that this value not be changed. The value of MC_SERVICES_P9 must be the same on all nodes connected by MEMORY CHANNEL. 2 MINCLASSPRI If class scheduling is enabled, MINCLASSPRI sets the minimum range in the priority range of class-scheduled processes. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. MINCLASSPRI is a DYNAMIC parameter. 2 MINWSCNT The value specified by MINWSCNT is added to the size of the process header to establish the minimum working set size. On Alpha and Integrity servers, MINWSCNT sets the minimum number of pages required for the execution of a process. The default value is 20; the minimum value is 10. MINWSCNT is an AUTOGEN parameter. 2 MMG_CTLFLAGS MMG_CTLFLAGS is a bitmask used to enable or disable memory management-related activities. The first two bits, 0 and 1, control the proactive memory reclamation mechanisms. Bit 2 controls deferred memory testing. The following bit mask values are defined: Bit Description 0 If this bit is set, reclamation is enabled by trimming from periodically executing, but otherwise idle, processes. This occurs when the size of the free list plus the modified list drops below two times the value of FREEGOAL. This function is disabled if the bit is clear. 1 If this bit is set, reclamation is enabled by outswapping processes that have been idle for longer than LONGWAIT seconds. This occurs when the size of the free list drops below FREEGOAL. This function is disabled if the bit is clear. 2 Controls deferred memory testing (only on AlphaServer 4100 systems). You can use this bit to speed up elapsed bootstrap time by controlling when memory is tested: o If the bit is clear (the default), OpenVMS tests memory as a background activity, which might or might not complete before the end of the bootstrap process. o If the bit is set, all memory is tested in the bootstrap process by the end of the EXEC_INIT phase (that is, before IPL is lowered from 31). 3 Reserved to OpenVMS use; must be zero. 4 If this bit is clear (the default), all page sizes supported by hardware can be used to map resident memory sections on Integrity servers. If this bit is set, page sizes on Integrity servers are limited to the maximum GH factor available on Alpha systems (512 * ). 5-7 Reserved for future use. MMG_CTLFLAGS is an AUTOGEN and DYNAMIC parameter. 2 MOUNTMSG_(D) MOUNTMSG controls whether or not the messages that log volume mounts appear on the operator's terminal and in the operator's log. The default value of 0 disables reporting of these messages. This parameter does not control the messages generated by mount assistance requests. MOUNTMSG is a DYNAMIC parameter. 2 MPDEV_AFB_INTVL (Alpha and Integrity servers) MPDEV_AFB_INTVL specifies the automatic failback interval in seconds. The automatic failback interval is the minimum number of seconds that must elapse before the system attempts another failback from an MSCP path to a direct path on the same device. MPDEV_POLLER must be set to ON to enable automatic failback. You can disable automatic failback without disabling the poller by setting MPDEV_AFB_INTVL to 0. The default is 300 seconds. 2 MPDEV_D* (Alpha and Integrity servers) MPDEV_D1 through MPDEV_D4 are reserved for use by the operating system. 2 MPDEV_ENABLE (Alpha and Integrity servers) MPDEV_ENABLE enables the formation of multipath sets when set to ON (1). If MPDEV_ENABLE is set to OFF (0), the formation of additional multipath sets and the addition of new paths to existing multipath sets are disabled. However, existing multipath sets remain in effect. The default is ON. MPDEV_REMOTE and MPDEV_AFB_INTVL have no effect when MPDEV_ENABLE is set to OFF. 2 MPDEV_LCRETRIES (Alpha and Integrity servers) MPDEV_LCRETRIES controls the number of times the system retries the direct paths to the controller that the logical unit is online to, before moving on to direct paths to the other controller, or to an MSCP served path to the device. The valid range for retries is 1 through 256. The default is 1. 2 MPDEV_POLLER (Alpha and Integrity servers) MPDEV_POLLER enables polling of the paths to multipath set members when set to ON (1). Polling allows early detection of errors on inactive paths. If a path becomes unavailable or returns to service, the system manager is notified with an OPCOM message. When set to OFF (0), multipath polling is disabled. The default is ON. Note that this parameter must be set to ON to use the automatic failback feature. 2 MPDEV_REMOTE (Alpha and Integrity servers) MPDEV_REMOTE enables MSCP served paths to become members of a multipath set when set to ON (1). When set to OFF (0), only local paths to a SCSI or Fibre Channel device is used in the formation of additional multipath sets. However, setting this parameter to OFF does not have any effect on existing multipath sets that have remote paths. To use multipath failover to a served path, MPDEV_REMOTE must be enabled on all systems that have direct access to shared SCSI/Fibre Channel devices. The first release to provide this feature is OpenVMS Alpha Version 7.3-1. Therefore, all nodes on which MPDEV_REMOTE is enabled must be running OpenVMS Alpha Version 7.3-1 (or later). If MPDEV_ENABLE is set to OFF (0), the setting of MPDEV_REMOTE has no effect because the addition of all new paths to multipath sets is disabled. The default is ON. 2 MPW_HILIMIT MPW_HILIMIT sets an upper limit for the modified-page list. When the list accumulates the number of pages specified by this limit, writing of the list begins. The pages that are written are then transferred to the free-page list. If MPW_HILIMIT is too low, excessive page faulting can occur from the page file. If it is too high, too many physical pages can be consumed by the modified-page list. If you increase MPW_HILIMIT, you might also need to increase MPW_WAITLIMIT. Note that if MPW_WAITLIMIT is less than MPW_HILIMIT, a system deadlock occurs. The values for the two parameters are usually equal. MPW_HILIMIT has the AUTOGEN and GEN attributes. 2 MPW_IOLIMIT MPW_IOLIMIT specifies the number of outstanding I/Os to the modified-page writer. On Alpha and Integrity servers, MPW_IOLIMIT is an AUTOGEN-altered parameter. 2 MPW_LOLIMIT MPW_LOLIMIT sets a lower limit for the modified-page list. When writing of the list causes the number of pages on the list to drop to or below this limit, writing stops. MPW_LOLIMIT ensures that a certain number of pages are available on the modified-page list for page faults. If the number is too small, the caching effectiveness of the modified-page list is reduced. If it is too high, less memory is available for processes, so that swap (and page) may increase. MPW_LOLIMIT has the AUTOGEN and GEN attributes. 2 MPW_LOWAITLIMIT MPW_LOWAITLIMIT specifies the threshold at which processes in the miscellaneous wait state MPWBUSY are allowed to resume. MPW_LOWAITLIMIT increases system performance for fast processors with large memories by reducing the amount of time processes spend in the MPWBUSY wait state. MPW_LOWAITLIMIT has the AUTOGEN and DYNAMIC attributes. 2 MPW_PRIO MPW_PRIO sets the priority of I/O transfers initiated by the modified page writer. The maximum value is 31, the minimum is 0, and the default is 4. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 MPW_THRESH MPW_THRESH sets a lower bound of pages that must exist on the modified-page list before the swapper writes this list to acquire free pages. If this requirement is met, the swapper tries to write the modified-page list rather than taking pages away from or swapping out a process. MPW_THRESH has the DYNAMIC attribute. On Alpha and Integrity servers, MPW_THRESH is also an AUTOGEN parameter. 2 MPW_WAITLIMIT MPW_WAITLIMIT sets the number of pages on the modified-page list that causes a process to wait until the next time the modified- page writer writes the modified list. This parameter limits the rate at which any single process can produce modified pages. If this value is less than MPW_HILIMIT, a system deadlock occurs. The value for this parameter is normally equal to MPW_HILIMIT. MPW_WAITLIMIT has the AUTOGEN and DYNAMIC attributes. 2 MPW_WRTCLUSTER MPW_WRTCLUSTER sets the number of pages to be written during one I/O operation from the modified-page list to the page file or a section file. The actual size of the cluster may be limited by the number of pages available for the I/O operation. This parameter can range in value from 16 to 120, in multiples of 8. Each page in the cluster requires 6 bytes of permanently resident memory. If MPW_WRTCLUSTER is too small, it takes many I/O operations to empty the modified-page list. If MPW_WRTCLUSTER is too large for the speed of the disk that holds the page file, other I/O operations are held up for the modified-page list write. On Alpha and Integrity servers, the MPW_WRTCLUSTER default value is 64 8192-byte pages; its maximum value is 512 8192-byte pages; and its minimum value is 16 8192-byte pages. MPW_WRTCLUSTER has the AUTOGEN and GEN attributes. 2 MSCP_BUFFER This buffer area is the space used by the server to transfer data between client systems and local disks. On Alpha and Integrity servers, MSCP_BUFFER specifies the number of pagelets to be allocated to the MSCP server's local buffer area. MSCP_BUFFER is an AUTOGEN and FEEDBACK parameter. 2 MSCP_CMD_TMO MSCP_CMD_TMO is the time in seconds that the OpenVMS MSCP server uses to detect MSCP command timeouts. The MSCP Server must complete the command within a built-in time of approximately 40 seconds plus the value of the MSCP_CMD_TMO parameter. The MSCP_CMD_TMO default value of 0 is normally adequate. A value of 0 provides the same behavior as in previous releases of OpenVMS (which did not have an MSCP_CMD_TMO system parameter). A nonzero setting increases the amount of time before an MSCP command times out. If command timeout errors are being logged on client nodes, setting the parameter to a nonzero value on OpenVMS servers may reduce the number of errors logged. As the value of the MSCP_CMD_TMO increases, the number of client MSCP command timeouts will decrease, at the cost of increased time to detect a faulty MSCP controller or MSCP-served device. If you need to decrease the number of command timeout errors, VSI recommends that you set an initial value of 60. If timeout errors continue to be logged, you can increase this value in increments of 20 seconds. MSCP_CMD_TMO is a DYNAMIC parameter. 2 MSCP_CREDITS MSCP_CREDITS specifies the number of outstanding I/O requests that can be active from one client system. The default value is currently 32. Unless a system has very constrained memory available, VSI recommends that these values not be increased. 2 MSCP_LOAD MSCP_LOAD controls the loading of the MSCP server during a system boot. Specify one of the following values: Value Description 0 Do not load the MSCP server. This is the default value. 1 Load the MSCP server and serve disks as specified by the MSCP_SERVE_ALL parameter. MSCP_LOAD has the AUTOGEN attribute. 2 MSCP_SERVE_ALL MSCP_SERVE_ALL is a bit mask that controls disk serving in an OpenVMS Cluster. A disk is served regardless of its allocation class unless bit 3 has a value of 1. Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving the system disk and serving locally attached disks. To specify such a combination, add the values of each type, and specify the sum. In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available disks is restricted to serving all disks except those whose allocation class does not match the system's node allocation class (prior to Version 7.2). To specify this type of serving, use the value 9 (which sets bit 0 and bit 3). The following table describes the serving type controlled by each bit and its decimal value: Bit and Value When Set Description Bit 0 (1) Serve all available disks (locally attached and those connected to HSx and DSSI controllers). Disks with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are also served if bit 3 is not set. Bit 1 (2) Serve locally attached (non-HSx and DSSI) disks. Bit 2 (4) Serve the system disk. This is the default setting. This setting is important when other nodes in the cluster rely on this system being able to serve its system disk. This setting prevents obscure contention problems that can occur when a system attempts to complete I/O to a remote system disk whose system has failed. Bit 3 (8) Restrict the serving specified by bit 0. All disks except those with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are served. This is pre-Version 7.2 behavior. If your cluster includes systems running OpenVMS 7.1-x or earlier, and you want to serve all available disks, you must specify 9, the result of setting this bit and bit 0. Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings: 0 - Do not serve any disks (the default for earlier versions of OpenVMS). 1 - Serve all available disks. 2 - Serve only locally attached (non-HSx and non-DSSI) disks. If the MSCP_LOAD system parameter is 0, MSCP_SERVE_ALL is ignored. 2 MULTIPROCESSING MULTIPROCESSING controls the loading of the system synchronization image. Specify one of the following values: Value Description 0 Load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. 1 If the CPU type is capable of SMP and two or more CPUs are present on the system, load the full-checking multiprocessing synchronization image SYSTEM_SYNCHRONIZATION.EXE. Otherwise, load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. 2 Always load the full-checking version SYSTEM_SYNCHRONIZATION.EXE, regardless of system configuration or CPU availability. 3 If the CPU type is capable of SMP and two or more CPUs are present on the system, load the optimized streamlined multiprocessing image: o On Alpha and Integrity servers, this image is SYSTEM_SYNCHRONIZATION_MIN.EXE. Otherwise, load the uniprocessing synchronization image SYSTEM_SYNCHRONIZATION_UNI.EXE. The default value is 3. 4 Always load the streamlined multiprocessing image SYSTEM_SYNCHRONIZATION_MIN.EXE, regardless of system configuration or CPU availability. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting MULTIPROCESSING to 2. 2 MULTITHREAD MULTITHREAD controls the availability of kernel threads functions. Specify one of the following values: Value Description 0 Both Thread Manager upcalls and the creation of multiple kernel threads are disabled. 1 Thread Manager upcalls are enabled; the creation of multiple kernel threads is disabled. 2-256 (Alpha Both Thread Manager upcalls and the creation and Integrity of multiple kernel threads are enabled. The servers) number specified represents the maximum number of kernel threads that can be created for a single process. The maximum value for MULTITHREAD is 256. MULTITHREAD is an AUTOGEN and DYNAMIC parameter. 2 MVSUPMSG_INTVL (Alpha and Integrity servers) The system suppresses mount verification start and end messages for fibre channel disk devices if mount verification completes on the first attempt and if mount verification does not occur too often. MVSUPMSG_NUM and this parameter establish this limit. The system issues a mount verification message after a sequence of MVSUPMSG_NUM mount verifications have gone unannounced on a specific fibre channel disk device within a span of MVSUPMSG_ INTVL seconds. If this parameter is zero, all mount verification messages are announced. MVSUPMSG_INTVL is a DYNAMIC parameter. 2 MVSUPMSG_NUM (Alpha and Integrity servers) The system suppresses mount verification start and end messages for fibre channel disk devices if mount verification completes on the first attempt and if mount verification does not occur too often. MVSUPMSG_INTVL and this parameter establish this limit. The system issues a mount verification message after a sequence of MVSUPMSG_NUM mount verifications have gone unannounced on a specific fibre channel disk device within a span of MVSUPMSG_ INTVL seconds. If this parameter is zero, all mount verification messages are announced. MVSUPMSG_NUM is a DYNAMIC parameter. 2 MVTIMEOUT MVTIMEOUT is the time in seconds that a mount verification attempt continues on a given disk volume. If the mount verification does not recover the volume within that time, the I/O operations outstanding to the volume terminate abnormally. MVTIMEOUT is a DYNAMIC parameter. On Alpha and Integrity servers, MVTIMEOUT is also an AUTOGEN parameter. 2 NET_CALLOUTS NET_CALLOUTS is normally set to 0. A value of 255 indicates that no attempt is to be made to assign a new proxy connection to an active server, but that a new process must be started to invoke the installation security policy callout modules in LOGINOUT.EXE. Values 1 through 254 are reserved for future use. NET_CALLOUTS is a DYNAMIC parameter. 2 NISCS_CONV_BOOT NISCS_CONV_BOOT controls whether a conversational boot is permitted during a remote system boot. The default value of 0 specifies that conversational boots are not permitted. 2 NISCS_LOAD_PEA0 NISCS_LOAD_PEA0 controls whether the NI-SCS port driver PEDRIVER is loaded during system boot. The default of 0 specifies that the PEDRIVER is not loaded. 2 NISCS_MAX_PKTSZ This parameter specifies an upper limit on the size, in bytes, of the user data area in the largest packet sent by NISCA on any local area network (LAN). NISCS_MAX_PKTSZ allows the system manager to change the packet size used for cluster communications on network communication paths. PEDRIVER automatically allocates memory to support the largest packet size that is usable by any virtual circuit connected to the system up to the limit set by this parameter. On Alpha and Integrity servers, to optimize performance, the default value is the largest packet size currently supported by OpenVMS. PEDRIVER uses NISCS_MAX_PKTSZ to compute the maximum amount of data to transmit in any LAN packet: LAN packet size <= LAN header (padded Ethernet format) + NISCS_MAX_PKTSZ + NISCS checksum (only if data checking is enabled) + LAN CRC or FCS The actual packet size automatically used by PEDRIVER might be smaller than the NISCS_MAX_PKTSZ limit for any of the following reasons: o On a per-LAN path basis, if PEdriver determines that the LAN path between two nodes, including the local and remote LAN adapters and intervening LAN equipment, can only convey a lesser size. In other words, only nodes with large-packet LAN adapters connected end-to-end by large-packet LAN equipment can use large packets. Nodes connected to large-packet LANs but having an end-to-end path that involves an Ethernet segment restrict packet size to that of an Ethernet packet (1498 bytes). o For performance reasons, PEDRIVER might further limit the upper bound on packet size so that the packets can be allocated from a lookaside list in the nonpaged pool. The actual memory allocation includes the required data structure overhead used by PEDRIVER and the LAN drivers, in addition to the actual LAN packet size. The following table shows the minimum NISCS_MAX_PKTSZ value required to use the maximum packet size supported by specified LAN types: Type of LAN Minimum Value for NISCS_MAX_PKTSZ Ethernet 1498 FDDI 4382 (before Version 7.3) 4396 (Version 7.3 and later) Gigabit Ethernet 8192 ATM 7606 Note that the maximum packet size for some Gigabit Ethernet adapters is larger than the maximum value of NISCS_MAX_PKTSZ (8192 bytes). See the LAN_FLAGS parameter for a description of how to enable jumbo frames on Gigabit Ethernet-that is, packet sizes larger than those noted for Ethernet. On Alpha and Integrity servers, NISCS_MAX_PKTSZ is an AUTOGEN parameter. 2 NISCS_PORT_SERV NISCS_PORT_SERV provides flag bits for PEDRIVER port services: o Setting bits 0 and 1 (hex bitmask value 3) enables data checking. o Setting bit 2 (hex bitmask value 4) enables data compression on all virtual channels (VCs) to nodes that support compression. The remaining bits are reserved for future use. Starting with OpenVMS Version 7.3-1, you can use the SCACP command SET VC/CHECKSUMMING to specify data checking on the VCs to certain nodes. You can do this on a running system. (For more information, see the SCACP documentation in the VSI OpenVMS System Management Utilities Reference Manual. Starting with OpenVMS Version 8.3, you can also use the SCACP command SET VC/COMPRESSION to specify data compression on the on the VCs to certain nodes. You can use SCACP to enable either data checking or data compression on a running system. (See the SCACP documentation in the the VSI OpenVMS System Management Utilities Reference Manual for more information. Also starting with OpenVMS Version 8.3, the NISCS_PORT_SERV system parameter is dynamic, that is, changing the setting of this parameter no longer requires a reboot. Furthermore, this parameter applies to all virtual circuits between the node on which it is set and other nodes in the cluster. NISCS_PORT_SERV has the DYNAMIC and AUTOGEN attributes. 2 NOAUTOCONFIG NOAUTOCONFIG controls whether all devices are automatically configured when the system boots. The default value of 0 sets the system to automatically configure all devices. Set NOAUTOCONFIG to 1 (no automatic configuration) only for debugging purposes. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. NOAUTOCONFIG is a DYNAMIC parameter. 2 NOCLUSTER NOCLUSTER controls whether page read clustering is inhibited when the system boots. Set NOCLUSTER to 1 (inhibit page read clustering) only for debugging purposes. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 NOPGFLSWP If enabled, NOPGFLSWP disables swapping into page files. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 NPAGECALC NPAGECALC controls whether the system automatically calculates the initial size for nonpaged dynamic memory. VSI sets the default value of NPAGECALC to 1 only during the initial boot after an installation or upgrade. When the value of NPAGECALC is 1, the system calculates an initial value for the NPAGEVIR and NPAGEDYN system parameters. This calculated value is based on the amount of physical memory in the system. NPAGECALC's calculations do not reduce the values of NPAGEVIR and NPAGEDYN from the values you see or set at the SYSBOOT prompt. However, NPAGECALC's calculation might increase these values. AUTOGEN sets NPAGECALC to 0. NPAGECALC should always remain 0 after AUTOGEN has determined more refined values for the NPAGEDYN and NPAGEVIR system parameters. 2 NPAGEDYN NPAGEDYN sets the size of the nonpaged dynamic pool in bytes. This figure is rounded down to an integral number of pages. NPAGEDYN establishes the initial setting of the nonpaged pool size, but the pool size can be increased dynamically. To set a value for this parameter, use AUTOGEN initially, and then monitor the amount of space actually used with the DCL command SHOW MEMORY/POOL/FULL. For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory. AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT. NPAGEDYN has AUTOGEN, FEEDBACK, GEN, and MAJOR attributes. 2 NPAGERAD (Alpha and Integrity servers) NPAGERAD specifies the total number of bytes of nonpaged pool that will be allocated for Resource Affinity Domains (RADs) other than the base RAD. For platforms that have no RADs, NPAGERAD is ignored. Notice that NPAGEDYN specifies the total amount of nonpaged pool for all RADs. Also notice that the OpenVMS system might round the specified values higher to an even number of pages for each RAD, which prevents the base RAD from having too little nonpaged pool. For example, if the hardware is an AlphaServer GS160 with 4 RADs: NPAGEDYN = 6291456 bytes NPAGERAD = 2097152 bytes In this case, the OpenVMS system allocates a total of approximately 6,291,456 bytes of nonpaged pool. Of this amount, the system divides 2,097,152 bytes among the RADs that are not the base RAD. The system then assigns the remaining 4,194,304 bytes to the base RAD. NOTE The system actually rounds up to an even number of pages on each RAD. In addition, the base RAD is never assigned a value less than the smaller of the value of NPAGEDYN and 4 megabytes. On AlphaServer GS series processors on OpenVMS systems prior to Version 7.3-1, system managers frequently saw pool expansion that increasing NPAGEDYN did not reduce. This problem was caused by leaving NPAGERAD at its default value of 0. Starting with OpenVMS Version 7.3-1, when NPAGERAD is 0 (the default), the system calculates a value to use for NPAGERAD with the following formula: Base RAD memory NPAGEDYN * (1- --------------- ) Total memory This calculation gives more pool to the non-base RADs than before and, therefore, reduces the expansion of non-base RADs. NPAGERAD has the GEN attribute. 2 NPAGEVIR NPAGEVIR defines the maximum size to which NPAGEDYN can be increased. If this value is too small, the system can hang. If NPAGEVIR is too large, the result is a penalty of 4 bytes per extra page on VAX and 8 bytes per extra page on Alpha and Integrity servers. For the benefit of OpenVMS VAX systems with limited physical memory, AUTOGEN logs a warning message in its report if NPAGEDYN exceeds 10 percent of physical memory or if NPAGEVIR exceeds 33 percent of physical memory. AUTOGEN also limits its own calculated value for NPAGEDYN to 20 percent of physical memory, and limits NPAGEVIR to 50 percent of physical memory. These calculated values are adequate for most workstations and systems with 16 or fewer megabytes of physical memory. If your system requires a larger value, you can override the AUTOGEN calculated values by setting higher values in MODPARAMS.DAT. NPAGEVIR has AUTOGEN and GEN attributes. 2 NPAG_AGGRESSIVE Beginning with OpenVMS Version 8.2, the default values of NPAG_ AGGRESSIVE and NPAG_GENTLE are 100. A value of 100 turns off both gentle and aggressive reclamation of nonpaged pool lookaside lists. In many cases, when pool reclamation moves small packets from the lookaside lists back to the variable list, the result is fragmentation of the variable list. This fragmentation appears as many small packets at the front of the variable list and a few large packets at the end of the list. When an allocation occurs for a packet that is larger than any of the lookaside lists, the system must find a large enough packet on the variable list. When heavily fragmented, the entire variable list often must be searched to find a large enough packet. Because the variable list is kept in address order, when a large packet is deallocated, the entire list must be searched again to deallocate the packet. Under these conditions, system performance can be severely degraded. For this reason, VSI recommends that you turn off pool reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system parameters set to 100. NPAG_AGGRESSIVE is a DYNAMIC parameter. 2 NPAG_BAP_MAX (Alpha and Integrity servers) NPAG_BAP_MAX is the size in bytes of the bus addressable pool (BAP) that the system creates under normal circumstances. See also NPAG_BAP_MIN. 2 NPAG_BAP_MAX_PA (Alpha and Integrity servers) NPAG_BAP_MAX_PA is the highest physical address in megabytes that is allowed in bus addressable pool (BAP). 2 NPAG_BAP_MIN (Alpha and Integrity servers) NPAG_BAP_MIN is the size in bytes of the bus addressable pool (BAP) that the system creates when memory resources are unusually constrained. 2 NPAG_BAP_MIN_PA (Alpha and Integrity servers) NPAG_BAP_MIN_PA specifies the lowest physical address in megabytes that is allowed in bus addressable pool (BAP). 2 NPAG_GENTLE Beginning with Version 8.2, the default values of NPAG_AGGRESSIVE and NPAG_GENTLE are 100. A value of 100 turns off both gentle and aggressive reclamation of nonpaged pool lookaside lists. In many cases, when pool reclamation moves small packets from the lookaside lists back to the variable list, the result is fragmentation of the variable list. This fragmentation appears as many small packets at the front of the variable list and a few large packets at the end of the list. When an allocation occurs for a packet that is larger than any of the lookaside lists, the system must find a large enough packet on the variable list. When heavily fragmented, the entire variable list often must be searched to find a large enough packet. Because the variable list is kept in address order, when a large packet is deallocated, the entire list must be searched again to deallocate the packet. Under these conditions, system performance can be severely degraded. For this reason, VSI recommends that you turn off pool reclamation but keep both NPAG_AGGRESSIVE and NPAG_GENTLE system parameters set to 100. NPAG_GENTLE is a DYNAMIC parameter. 2 NPAG_INTERVAL NPAG_INTERVAL is the number of seconds between passes of nonpaged-pool gentle reclamation. NPAG_INTERVAL is a DYNAMIC parameter. 2 NPAG_RING_SIZE NPAG_RING_SIZE represents the number of entries in the ring buffer. 2 PAGED_LAL_SIZE PAGED_LAL_SIZE sets the maximum size, in bytes, to use for the page dynamic pool lookaside lists. Use of these lookaside lists can reduce paged dynamic pool variable freelist fragmentation and improve paged pool allocation and deallocation performance. By default, PAGED_LAL_SIZE is set to 0, which disables the use of the paged dynamic pool lookaside lists. For environments experiencing paged pool variable freelist fragmentation a modest PAGED_LAL_SIZE, 512, has been adequate to improve paged pool performance and reduce fragmentation. If this parameter is made large and later decreased in size, some paged pool packets can be left unused until the parameter is made larger again, or the lookaside lists are reclaimed from due to a paged pool shortage. The paged dynamic pool lookaside lists will not occupy more than three-quarters of the available paged pool. PAGED_LAL_SIZE has DYNAMIC, GEN, and MAJOR attributes. 2 PAGFILCNT On Alpha and Integrity servers, beginning in OpenVMS Version 7.3, this parameter is obsolete. PAGFILCNT has the GEN attribute on VAX systems. 2 PAGTBLPFC PAGTBLPFC specifies (in pages) the maximum number of page tables to read to satisfy a fault for a nonresident page table. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 PAMAXPORT PAMAXPORT specifies the maximum port number to be polled on each CI and DSSI. The CI and DSSI port drivers poll to discover newly initialized ports or the absence/failure of previously responding remote ports. A system does not detect the existence of ports whose port numbers are higher than this parameter's value. Thus, set this parameter to a value that is equal to or greater than the highest port number being used on any CI or DSSI connected to the system. You can decrease this parameter to reduce polling activity if the hardware configuration has fewer than 16 ports. For example, if the CI or DSSI with the largest configuration has a total of 5 ports assigned to port numbers 0 through 4, you could set PAMAXPORT to 4. If CI or DSSI devices are not configured on your system, this parameter is ignored. The default for this parameter is 15 (poll for all possible ports 0 through 15). VSI recommends that you set this parameter to the same value on each cluster computer. PAMAXPORT is a DYNAMIC parameter. 2 PANOPOLL Disables CI and DSSI polling for ports if set to 1. (The default is 0.) When PANOPOLL is set, a computer does not discover that another computer has shut down or powered down promptly and does not discover a new computer that has booted. This parameter is useful when you want to bring up a computer detached from the rest of the cluster for checkout purposes. PANOPOLL is functionally equivalent to uncabling the system from the DSSI or star coupler. This parameter does not affect OpenVMS Cluster communications by LAN. The default value of 0 is the normal setting and is required if you are booting from an HSC controller or if your system is joining an OpenVMS Cluster. This parameter is ignored if no CI or DSSI devices are configured on your system. PANOPOLL is a DYNAMIC parameter. 2 PANUMPOLL PANUMPOLL establishes the number of CI and DSSI ports to be polled each polling interval. The normal setting for PANUMPOLL is 16. On systems with less powerful CPUs, the parameter may be useful in applications sensitive to the amount of contiguous time that the system spends at IPL 8. Reducing PANUMPOLL reduces the amount of time spent at IPL 8 during each polling interval, while increasing the number of polling intervals needed to discover new or failed ports. If CI or DSSI devices are not configured on your system, this parameter is ignored. PANUMPOLL is a DYNAMIC parameter. 2 PAPOLLINTERVAL Specifies, in seconds, the polling interval the CI port driver uses to poll for a newly booted computer, a broken port-to-port virtual circuit, or a failed remote computer. This parameter trades polling overhead against quick response to virtual circuit failures. VSI recommends that you use the default value for this parameter. VSI recommends that you set this parameter to the same value on each cluster computer. PAPOLLINTERVAL is a DYNAMIC parameter. 2 PAPOOLINTERVAL Specifies, in seconds, the interval at which the port driver checks available nonpaged pool after a pool allocation failure. This parameter trades faster response to pool allocation failures against increased polling overhead. VSI recommends that you use the default value for this parameter. If CI or DSSI devices are not configured on your system, this parameter is ignored. PAPOOLLINTERVAL is a DYNAMIC parameter. 2 PASANITY PASANITY controls whether the CI and DSSI port sanity timers are enabled to permit remote systems to detect a system that has been hung at IPL 8 or above for 100 seconds. It also controls whether virtual circuit checking gets enabled on the local system. The TIMVCFAIL parameter controls the time (1-99 seconds). PASANITY is normally set to 1 and should be set to 0 only when you are debugging with XDELTA or planning to halt the CPU for periods of 100 seconds or more. PASANITY is only semidynamic. A new value of PASANITY takes effect on the next CI or DSSI port reinitialization. If CI or DSSI devices are not configured on your system, this parameter is ignored. 2 PASTDGBUF The number of datagram receive buffers to queue initially for the cluster port driver's configuration poller. The initial value is expanded during system operation, if needed. Memory Channel devices ignore this parameter. PASTDGBUF is an AUTOGEN parameter. 2 PASTIMOUT The basic interval at which the CI port driver wakes up to perform time-based bookkeeping operations. It is also the period after which a timeout is declared if no response to a start handshake datagram has been received. If CI or DSSI devices are not configured on your system, this parameter is ignored. The default value should always be adequate. PASTIMOUT is a DYNAMIC parameter. 2 PE1-6 PE1, PE2, PE3, PE4, PE5, PE6 are reserved for VSI use only. These parameters are for cluster algorithms and their usages can change from release to release. VSI recommends using the default values for these special parameters. 2 PFCDEFAULT On Alpha and Integrity servers during execution of programs, PFCDEFAULT controls the number of image pagelets read from disk per I/O operation when a page fault occurs. The PFCDEFAULT maximum default value is 2032 512-byte pagelets (127 8192-byte Alpha and Integrity server pages). The read I/O operations can take place from an image file or from the page file. The actual size of the cluster can be less than PFCDEFAULT, depending on the size of image sections and the pattern of page references. The value should not be greater than one-fourth the default size of the average working set to prevent a single page fault from displacing a major portion of a working set. Too large a value for PFCDEFAULT can hurt system performance. PFCDEFAULT can be overridden on an image-by-image basis with the CLUSTER option of the OpenVMS linker. PFCDEFAULT has the AUTOGEN and DYNAMIC attributes. 2 PFN_COLOR_COUNT (Alpha and Integrity servers) PFN_COLOR_COUNT specifies the number of buckets (colors) into which all members of the zeroed page list and all unencumbered members of the free page list are sorted. OpenVMS Alpha systems might derive a preferred page color from a request to map a given virtual page and attempt to map that virtual page to a PFN of matching "color." This results in less variance in which cache blocks are used when accessing that page. This might or might not improve performance, depending on the application. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. If you increase this parameter, you must also increase the ZERO_ LIST_HI system parameter. 2 PFRATH PFRATH specifies the page fault rate above which the limit of a working set is automatically increased. The unit of measure is the number of faults per 10 seconds of processor time. At a setting of 120, for example, the system automatically increases the limit of a working set if it is faulting more than 120 pages per 10 seconds. Decreasing the value of this parameter tends to increase the limits of the working sets, while increasing its value tends to decrease their limits. On Alpha and Integrity servers, the default value is 8 page faults every 10 seconds. PFRATH has the DYNAMIC and MAJOR attributes. On Alpha and Integrity servers, PFRATH also is an AUTOGEN-altered parameter. 2 PFRATL PFRATL specifies the page fault rate below which the limit of a working set is automatically decreased. The unit of measure is the number of faults per 10 seconds of processor time. At a setting of 1, for example, the system automatically decreases the limit of a working set if it is faulting less than 1 page every 10 seconds. Increasing the value of this parameter tends to decrease the limits of the working sets, while decreasing its value tends to increase their limits. PFRATL has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 PHYSICAL_MEMORY (Alpha and Integrity servers) PHYSICAL_MEMORY specifies the amount of physical memory available for use. The default setting is -1, which equates to all memory in the system. Decreasing this parameter allows you to test smaller configurations of memory without having to remove memory boards. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. Because of hardware configuration requirements on the AlphaServer ES47/ES80/GS1280 systems, VSI does not recommend altering the setting of the system parameter PHYSICAL_MEMORY from its default setting of -1. Artificially reducing the amount of memory can produce unpredictable results on these systems. PHYSICAL_MEMORY is an AUTOGEN parameter. PHYSICALPAGES is an AUTOGEN parameter. 2 PIOPAGES PIOPAGES specifies the size of the process I/O segment, which holds data structures and buffer pool space for RMS to use when it handles I/O that involves process-permanent files. Once PIOPAGES is reset in SYSGEN, any new process receives the changed value. Beginning with OpenVMS Version 7.2, the default value has been raised to 575. The setting has been raised to accommodate the increased demands for process-permanent memory that result from changes made to RMS file-naming parsing in Version 7.2. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. PIOPAGES is an AUTOGEN and DYNAMIC parameter. 2 PIXSCAN PIXSCAN specifies the number of process index slots scanned each second for computable or computable-outswapped processes. These processes receive an automatic priority boost for 1 quantum, unless the priority of the currently executing process is greater than 15. The priority boost is done to avoid potential deadlocks on the system. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. PIXSCAN is an AUTOGEN and DYNAMIC parameter. 2 POOLCHECK This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. POOLCHECK is used to investigate frequent and inexplicable failures in a system. When POOLCHECK is enabled, pool-checking routines execute whenever pool is deallocated or allocated. Two loadable forms of SYSTEM_PRIMITIVES.EXE are available at boot time. The default image, which contains no pool-checking code and no statistics maintenance, is loaded when POOLCHECK is set to zero. When POOLCHECK is set to a nonzero value, the monitoring version of SYSTEM_PRIMITIVES.EXE, which contains both pool-checking code and statistics maintenance, is loaded. Setting the SYSTEM_CHECK parameter to 1 has the effect of setting POOLCHECK to %X616400FF. For further information about pool checking, see the OpenVMS VAX Device Support Manual, (which is archived). POOLCHECK is a DYNAMIC parameter. However, for a change in its value to have any effect, POOLCHECK must be non-0 at boot time (to load the monitoring version of SYSTEM_PRIMITIVES.EXE). 2 POOLPAGING POOLPAGING enables (1) paging of pageable dynamic pool. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 POWEROFF POWEROFF enables or disables software requests to the console firmware to remove power from the system. This parameter should normally be turned ON (1) to allow software to make power-off requests. However, POWEROFF can be set to OFF (0) to disable software power-off requests. If firmware or hardware support for the power-off request is not implemented, the shut-down procedure will leave the system halted but fully powered. POWEROFF is a DYNAMIC parameter. 2 PQL_DASTLM PQL_DASTLM sets the default limit on the number of pending ASTs for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DASTLM has the DYNAMIC and GEN attributes. 2 PQL_DBIOLM PQL_DBIOLM sets the default buffered I/O count limit for the number of outstanding buffered I/O operations permitted to a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DBIOLM has the DYNAMIC and GEN attributes. 2 PQL_DBYTLM PQL_DBYTLM sets the default buffered I/O byte count limit for the amount of buffered space available to a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DBYTLM has the DYNAMIC and GEN attributes. 2 PQL_DCPULM PQL_DCPULM sets the default CPU time limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DCPULM specifies the time limit in increments of 10 milliseconds. The default value of 0 imposes no limit on CPU time usage and is typically the correct value for this parameter. PQL_DCPULM has the DYNAMIC and GEN attributes. 2 PQL_DDIOLM PQL_DDIOLM sets the default direct I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DDIOLM has the DYNAMIC and GEN attributes. 2 PQL_DENQLM PQL_DENQLM sets the default enqueue limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DENQLM has the DYNAMIC and GEN attributes. 2 PQL_DFILLM PQL_DFILLM sets the default open file limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DFILLM has the DYNAMIC and GEN attributes. 2 PQL_DJTQUOTA PQL_DJTQUOTA sets the default job table byte count quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DJTQUOTA specifies the number of bytes of paged pool allocated to the job table. The default value is usually adequate, unless a large number of job logical names or temporary mailboxes are used. PQL_DJTQUOTA is a DYNAMIC parameter. 2 PQL_DPGFLQUOTA PQL_DPGFLQUOTA sets the default page file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). VSI recommends that this parameter not be smaller than the PQL_DWSEXTENT parameter. PQL_DPGFLQUOTA has the DYNAMIC and GEN attributes. On VAX systems, PQL_DPGFLQUOTA is also an AUTOGEN parameter. 2 PQL_DPRCLM PQL_DPRCLM sets the default subprocess limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DPRCLM has the DYNAMIC and GEN attributes. 2 PQL_DTQELM PQL_DTQELM sets the default number of timer queue entries for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DTQELM has the DYNAMIC and GEN attributes. 2 PQL_DWSDEFAULT PQL_DWSDEFAULT sets the default working set size for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSDEFAULT has the AUTOGEN and GEN attributes. 2 PQL_DWSEXTENT PQL_DWSEXTENT sets the default working set extent for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_DWSQUOTA PQL_DWSQUOTA sets the default working set quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_DWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_MASTLM PQL_MASTLM sets a minimum limit on the number of pending ASTs for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MASTLM has the DYNAMIC and GEN attributes. 2 PQL_MBIOLM PQL_MBIOLM sets the minimum buffered I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MBIOLM has the DYNAMIC and GEN attributes. 2 PQL_MBYTLM PQL_MBYTLM sets the minimum buffered I/O byte limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MBYTLM has the DYNAMIC and GEN attributes. 2 PQL_MCPULM PQL_MCPULM sets the minimum CPU time limit in increments of 10 milliseconds for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MCPULM has the DYNAMIC and GEN attributes. 2 PQL_MDIOLM PQL_MDIOLM sets the minimum direct I/O limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MDIOLM has the DYNAMIC and GEN attributes. 2 PQL_MENQLM PQL_MENQLM sets the minimum limit on the number of locks that can be queued at one time by a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MENQLM has the DYNAMIC and GEN attributes. 2 PQL_MFILLM PQL_MFILLM sets the minimum open file limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MFILLM has the DYNAMIC and GEN attributes. 2 PQL_MJTQUOTA PQL_MJTQUOTA sets the minimum job table byte count quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MJTQUOTA is a DYNAMIC parameter. 2 PQL_MPGFLQUOTA On VAX systems, PQL_MPGFLQUOTA sets the minimum page file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). VSI recommends that this parameter be no smaller than PQL_MWSEXTENT. On Alpha and Integrity servers, PQL_MPGFLQUOTA sets the minimum pagelet file quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MPQFLQUOTA has the DYNAMIC and GEN attributes. On VAX systems, PQL_MPQFLQUOTA is also an AUTOGEN parameter. 2 PQL_MPRCLM PQL_MPRCLM sets the minimum subprocess limit for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MPRCLM has the DYNAMIC and GEN attributes. 2 PQL_MTQELM PQL_MTQELM sets the minimum number of timer queue entries for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). PQL_MTQELM has the DYNAMIC and GEN attributes. 2 PQL_MWSDEFAULT PQL_MWSDEFAULT sets the minimum default working set size for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity that is set for a user in AUTHORIZE. PQL_MWSDEFAULT has the AUTOGEN and GEN attributes. 2 PQL_MWSEXTENT PQL_MWSEXTENT sets the minimum working set extent for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity set for a user in AUTHORIZE. PQL_MWSEXTENT has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PQL_MWSQUOTA PQL_MWSQUOTA sets the minimum working set quota for a process created by the Create Process ($CREPRC) system service or the DCL command RUN (Process). This value overrides a smaller quantity set for a user in AUTHORIZE. PQL_MWSQUOTA has the AUTOGEN, DYNAMIC, and GEN attributes. 2 PRCPOLINTERVAL PRCPOLINTERVAL specifies, in seconds, the polling interval used to look for Systems Communications Services (SCS) applications, such as the connection manager and mass storage control protocol disks, on other nodes. All discovered nodes are polled during each interval. This parameter trades polling overhead against quick recognition of new systems or servers as they appear. PRCPOLINTERVAL is a DYNAMIC parameter. On Alpha and Integrity servers, PRCPOLINTERVAL is also an AUTOGEN parameter. 2 PRIORITY_OFFSET PRIORITY_OFFSET specifies the difference in priority required by the scheduler for one process to preempt the current process. A value of 2, for example, means that if the current process is executing at priority 1, a computable process at priority 2 or 3 is not allowed to preempt the current process. However, a priority 4 or higher process can preempt the current process. This mechanism affects only normal priority (0-15) processes. The default value is 0. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 PROCSECTCNT PROCSECTCNT sets the number of section descriptors that a process can contain. Each section descriptor increases the fixed portion of the process header by 32 bytes. Set a value greater than the maximum number of image sections in any section to be run, as indicated by the linkage memory allocation map for the image. PROCSECTCNT has the AUTOGEN and GEN attributes. 2 PU_OPTIONS PU_OPTIONS is reserved for VSI use only. 2 QDSKINTERVAL QDSKINTERVAL establishes, in seconds, the disk quorum polling interval. The default value is 3. 2 QDSKVOTES QDSKVOTES specifies the number of votes contributed by a quorum disk in a cluster. 2 QUANTUM QUANTUM defines the following: o Processor time: maximum amount of processor time a process can receive before control passes to another process of equal priority that is ready to compute o Balance set residency: minimum amount of service a compute- state process must receive before being swapped out to secondary storage QUANTUM has the DYNAMIC and MAJOR attributes. On Alpha and Integrity servers, QUANTUM also has the AUTOGEN attribute. 2 RAD_SUPPORT RAD_SUPPORT enables RAD-aware code to be executed on systems that support Resource Affinity Domains (RADs); for example, AlphaServer GS160 systems and Integrity cell-based servers or BL8x0c i2 servers. A RAD is a set of hardware components (CPUs and memory) with common access characteristics. Bits are defined in the RAD_SUPPORT parameter as follows: RAD_SUPPORT (default is 207 for Alpha and 10944667 for Integrity servers) ___________________________________________________ 3 2 2 2 2 1 1 1 8 7 4 3 6 5 8 7 0 +-----+-----+-----------+-----------+-----------+ |00|00| skip|ss|gg|ww|pp|00|00|00|00|0p|df|cr|ae| +-----+-----+-----------+-----------+-----------+ Bit 0 (e): Enable - Enables RAD support Bit 1 (a): Affinity - Enables Soft RAD Affinity (SRA) scheduling Also enables the interpretation of the skip bits, 24-27. Bit 2 (r): Replicate - Enables system-space code replication Bit 3 (c): Copy - Enables copy on soft fault Bit 4 (f): Fault - Enables special page fault allocation Also enables the interpretation of the allocation bits, 16-23. Bit 5 (d): Debug - Reserved to VSI Bit 6 (p): Pool - Enables per-RAD non-paged pool Bits 7-15: - Reserved to VSI Bits 16-23: - If bit 4 is set, bits 16-23 are interpreted as follows: Bits 16,17 (pp): Process = Pagefault on process (non global) pages Bits 18,19 (ww): Swapper = Swapper's allocation of pages for processes Bits 20,21 (gg): Global = Pagefault on global pages Bits 22,23 (ss): System = Pagefault on system space pages Encodings for pp, ww, gg, ss: Current (0) - allocate PFNs from the current CPU's RAD Random (1) - allocate PFNs using the "random" algorithm Base (2) - allocate PFNs from the operating system's "base" RAD Home (3) - allocate PFNs from the current process's home RAD If bits 16-23 are 0, the defaults for pp, ww, gg, ss are interpreted as follows: Process = home RAD Swapper = current RAD (also sets home RAD for process) Global = random RAD System = base RAD Bits 24-27: - If bit 1 is set, bits 24-27 are interpreted as a skip count value (power of 2). Example: If bits 24-27 contain a 3, the skip count is 8. If bits 24-27 contain a 5, the skip count is 32. If bits 24-27 are 0, the default of 16 is used as the skip count. Bits 28-31: - Reserved to VSI For more information about using OpenVMS RAD features, see the OpenVMS Alpha Galaxy and Partitioning Guide or VSI OpenVMS Version 8.4 New Features and Documentation Overview. RAD_SUPPORT has the GEN attribute. REALTIME_SPTS has the DYNAMIC, GEN, and MAJOR attributes. 2 RECNXINTERVAL RECNXINTERVAL establishes the polling interval, in seconds, during which to attempt reconnection to a remote system. RECNXINTERVAL is a DYNAMIC parameter. On Alpha and Integrity servers, RECNXINTERVAL is also an AUTOGEN parameter. 2 RESALLOC RESALLOC controls whether resource allocation checking is performed. The default value of 0 disables resource allocation checking. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 RESHASHTBL RESHASHTBL defines the number of entries in the lock management resource name hash table. Each entry requires 4 bytes. A typical tuning goal is to have the RESHASHTBL parameter about four times larger than the total number of resources in use on the system. Managers of systems with memory constraints or systems that are not critically dependent on locking speed could set the table to a smaller size. RESHASHTBL has the AUTOGEN, FEEDBACK, and MAJOR attributes. 2 RJOBLIM RJOBLIM defines the maximum number of remote terminals allowed in the system at any one time. RJOBLIM is a DYNAMIC parameter. 2 RMS_CONPOLICY RMS_CONPOLICY specifies the policy to be used for dealing with high-contention write-shared files. This dynamic parameter can be used to ensure fairness between lock conversions and new lock requests. Possible values are the following: Value Explanation NEVER (Default) Never use the higher overhead option to improve fairness for any write-shared files accessed on the system; minimal overhead. SOMETIMES Use this option for fairer bucket access (but higher overhead) to any write-shared files with global buffers enabled that are accessed on the system. ALWAYS Use this option for fairer bucket access (but higher overhead) to all write-shared files accessed on the system. You can set this system parameter with the DCL command SET RMS_ DEFAULT/SYSTEM/CONTENTION_POLICY=value and display the parameter with the DCL command SHOW RMS_DEFAULT. RMS_CONPOLICY is a DYNAMIC parameter. 2 RMSD* RMSD1, RMSD2, RMSD3, RMSD4, RMSD5, RMSD6, and RMSD7 are special parameters reserved for VSI use. RMSD* parameters are DYNAMIC. 2 RMS_DFLRL This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. RMS_DFLRL is a DYNAMIC parameter. 2 RMS_DFMBC RMS_DFMBC specifies a default multiblock count only for record I/O operations, where count is the number of blocks to be allocated for each I/O buffer. You can set this system parameter with the DCL command SET RMS_ DEFAULT/SYSTEM and display the parameter with the SHOW RMS_ DEFAULT command. RMS_DFMBC is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFIDX RMS_DFMBFIDX establishes the default RMS multibuffer count for indexed sequential disk operations. This value defines the number of I/O buffers that RMS allocates for each indexed file. For sequential access, a larger number that allows some of the index buckets to remain in memory can improve performance. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFIDX is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFREL RMS_DFMBFREL establishes the default RMS multibuffer count for relative disk operations. This value defines the number of I/O buffers that RMS allocates for each relative file. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFREL is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSDK RMS_DFMBFSDK establishes the default RMS multibuffer count for sequential disk operations. This value defines the number of I/O buffers that RMS allocates for sequential disk files. The default value is usually adequate. However, if read-ahead or write-behind operations are used, a larger number improves performance. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSDK is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSMT RMS_DFMBFSMT establishes the default RMS multibuffer count for magnetic tape operations. This value defines the number of I/O buffers that RMS allocates for magnetic tape files. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSMT is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFMBFSUR RMS_DFMBFSUR establishes the default multibuffer count for unit record devices. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFMBFSUR is an AUTOGEN and DYNAMIC parameter. 2 RMS_DFNBC RMS_DFNBC specifies a default block count for network access to remote, sequential, indexed sequential, and relative files. The network block count value represents the number of blocks that RMS is prepared to allocate for the I/O buffers used to transmit and receive data. The buffer size used for remote file access, however, is the result of a negotiation between RMS and the remote file access listener (FAL). The buffer size chosen is the smaller of the two sizes presented. Thus, RMS_DFNBC places an upper limit on the network buffer size that is used. It also places an upper limit on the largest record that can be transferred to or from a remote file. In other words, the largest record that can be transferred must be less than or equal to RMS_DFNBC multiplied by 512 bytes. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_DFNBC is an AUTOGEN and DYNAMIC parameter. 2 RMS_EXTEND_SIZE RMS_EXTEND_SIZE specifies the number of blocks by which files are extended as they are written. This number should be chosen to balance the amount of extra disk space wasted at the ends of each file against the performance improvement provided by making large extents infrequently. When small disk quotas are used, specify a small number such as the disk cluster size to prevent the user's disk quota from being consumed. If the value of 0 is used, RMS allocates large extents and truncates the file back to its actual usage when it closes. You can set this system parameter with the DCL command SET RMS_DEFAULT/SYSTEM and display the parameter with SHOW RMS_ DEFAULT. RMS_EXTEND_SIZE is a DYNAMIC parameter. 2 RMS_FILEPROT RMS_FILEPROT determines the default file protection for system processes such as those that create the error log, operator log, and job controller. It also determines default file protection for processes created by the job controller (all interactive and batch processes). Because a process always inherits its default file protection from its creator process, RMS_FILEPROT determines default file protection only for users who do not execute the DCL command SET PROTECTION/DEFAULT in their login command procedures or during interactive sessions. The protection is expressed as a mask. (See the discussion of the $CRMPSC system service in the VSI OpenVMS System Services Reference Manual for more information about specifying protection masks.) By default, the mask is 64000 (decimal) or FA00 (hexadecimal), which represents the following protection: (S:RWED,O:RWED,G:RE,W:) 2 RMS_HEURISTIC This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. RMS_HEURISTIC is a DYNAMIC parameter. 2 RMS_PATH_TMO The RMS path cache in each process holds entries that translate DVI+DID+name to new DVI+DID. These are used to greatly speed up directory path walks. Cache entries representing ordinary directory lookups are invalidated through the volume directory sequence number mechanism (UDB$L_DIRSEQ), which is clocked on every volume dismount and each time a directory is deleted or renamed. However, there is no convenient mechanism for invalidating a cache entry that represents a symlink, whose interpretation is affected by logical names or modification of the symlink. The only way to eliminate stale cache entries is with a timeout. This parameter is the system-wide cache timeout. Special values: 1 = don't keep cache entries -1 = keep cache entries forever RMS_PATH_TMO is a DYNAMIC parameter. 2 RMS_PROLOGUE RMS_PROLOGUE specifies the default prologue RMS uses to create indexed files. The default value 0 specifies that RMS should determine the prologue based on characteristics of the file. A value of 2 specifies Prologue 2 or Prologue 1, and 3 specifies Prologue 3. The RMS prologues are described in the OpenVMS Record Management Services Reference Manual. RMS_PROLOGUE is a DYNAMIC parameter. 2 RMS_SEQFILE_WBH (Alpha and Integrity servers) RMS_SEQFILE_WBH can enable the RMS writebehind feature as a system default for any unshared sequential disk file if the file is opened for image I/O with write access specified. The possible settings are the following: Setting Description 0 (default) Do not enable writebehind feature. Preserve prior behavior of using writebehind only if the user requests it by setting RAB$V_WBH in RAB$L_ROP. 1 Enable writebehind feature as system default, including the allocation of at least two local buffers. RMS_SEQFILE_WBH is a DYNAMIC parameter. 2 S0_PAGING S0_PAGING controls paging of system code: o Setting bit 0 disables paging of all Exec code and data. o Setting bit 1 disables paging of all RMS code and data. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 S2_SIZE (Alpha and Integrity servers) S2_SIZE is the number of megabytes to reserve for S2 space. This value does not include the size required for extended file cache (XFC). 2 SAVEDUMP If the dump file is saved in the page file, SAVEDUMP specifies whether the page file is saved until the dump file is analyzed. The default value 0 specifies that the page file should not be retained. A value of 1 specifies that the dump written to the page file should be retained until either copied or released using the SDA utility. 2 SCHED_FLAGS Special DYNAMIC parameter reserved for VSI use. 2 SCH_HARD_OFFLD The scheduler hard off-load parameter is a CPU bitmask parameter. The bits correspond to CPU IDs. For any bit set, the OpenVMS scheduler does not schedule processes on this CPU unless the process has hard affinity set for the CPU. In addition, a process with the PRIMARY capability requirement will ignore the bit corresponding to the primary CPU. SCH_HARD_OFFLD is a DYNAMIC parameter. 2 SCH_SOFT_OFFLD The scheduler soft off-load parameter is a CPU bitmask parameter. The bits correspond to CPU IDs. For any bit set, the OpenVMS scheduler tries to avoid scheduling processes on this CPU. However, if no other idle CPUs exist, processes are still scheduled on this CPU. SCH_SOFT_OFFLD is a DYNAMIC parameter. 2 SCSBUFFCNT On VAX systems, SCSBUFFCNT is the number of buffer descriptors configured for all systems communication architecture (SCA). If an SCA device is not configured on your system, this parameter is ignored. Generally speaking, each data transfer needs a buffer descriptor and thus the number of buffer descriptors can be a limit on the number of possible simultaneous I/Os. Various performance monitors report when a system is out of buffer descriptors for a given workload which is an indication that a larger value for SCSBUFFCNT is worth considering. Note that AUTOGEN provides feedback for this parameter on VAX systems only. On Alpha and Integrity servers, the system communication services (SCS) buffers are allocated as needed, and SCSBUFFCNT is reserved for VSI use only. SCSBUFFCNT has the AUTOGEN, FEEDBACK, and GEN attributes. 2 SCSFLOWCUSH Specifies the lower limit for receive buffers at which point system communication services (SCS) starts to notify the remote SCS of new receive buffers. For each connection, SCS tracks the number of receive buffers available. SCS communicates this number to the SCS at the remote end of the connection. However, SCS does not need to do this for each new receive buffer added. Instead, SCS notifies the remote SCS of new receive buffers if the number of receive buffers falls as low as the SCSFLOWCUSH value. The default value is adequate on most systems. If a systems communication architecture (SCA) port is not configured on your system, this parameter is ignored. SCSFLOWCUSH is a DYNAMIC parameter. 2 SCSI_ERROR_POLL If an error occurs while a particular initiator is accessing a SCSI device, that error is latched for all other initiators and is not unlatched and reported to the other initiators until the next time they access the device. Therefore, if the other initiators do not access the device in a timely manner, the reporting of the error can be greatly delayed, which can cause confusion. The purpose of SCSI_ERROR_POLL is to cause OpenVMS to send a SCSI Test Unit Ready command every hour to each SCSI disk, in an attempt to force latched errors to become unlatched and to be reported immediately. SCSI_ERROR_POLL has a default value of 1. It can, however, be set to 0 by the user in order to stop the error polling activity. The parameter affects SCSI disks connected by Fibre Channel as well as parallel SCSI. If the disk has multiple paths, then the error polling is performed on all non-served paths to the disk. Tapes and other non-disk devices are not subject to this error polling, regardless of the parameter setting. SCSI_ERROR_POLL is a DYNAMIC parameter. SCSI_NOAUTO is a DYNAMIC parameter. 2 SCSICLUSTER_P[1-4] (Alpha only) SCSICLUSTER_P[1-4] parameters allow non-HP peripherals (CPU-lookalikes) in SCSI clusters. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SCSMAXDG This parameter is reserved for VSI use only. SCSMAXDG has the GEN attribute. 2 SCSMAXMSG This parameter is reserved for VSI use only. SCSMAXMSG has the GEN attribute. 2 SCSNODE SCSNODE specifies the name of the computer. This parameter is not dynamic. Specify SCSNODE as a string of up to six characters. Enclose the string in quotation marks. NOTE The maximum size of six characters is strictly enforced. SYSBOOT truncates the value of SCSNODE if the size of the system parameter is set to more than six characters. If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not specify the null string. If the computer is running DECnet for OpenVMS, the value must be the same as the DECnet node name. SCSNODE has the AUTOGEN and GEN attributes. 2 SCSRESPCNT SCSRESPCNT is the total number of response descriptor table entries (RDTEs) configured for use by all system applications. If SCA or DSA ports are not configured on your system, the system ignores SCSRESPCNT. SCSRESPCNT has the AUTOGEN, FEEDBACK, and GEN attributes. 2 SCSSYSTEMID Specifies a number that identifies the computer. This parameter is not dynamic. SCSSYSTEMID is the low-order 32 bits of the 48- bit system identification number. If the computer is in an OpenVMS Cluster, specify a value that is unique within the cluster. Do not use zero as the value. If the computer is running DECnet for OpenVMS, calculate the value from the DECnet address using the following formula: SCSSYSTEMID = ((DECnet area number) * 1024) + (DECnet node number) Example: If the DECnet address is 2.211, calculate the value as follows: SCSSYSTEMID = (2 * 1024) + 211 = 2259 SCSSYSTEMID has the GEN attribute. 2 SCSSYSTEMIDH Specifies the high-order 16 bits of the 48-bit system identification number. This parameter must be set to 0. It is reserved by VSI for future use. SCSSYSTEMIDH has the GEN attribute. 2 SECURITY_POLICY SECURITY_POLICY allows a system to run in a C2 or B1 configuration and to subset out particular pieces of functionality-to exclude functionality that is outside the evaluated configuration or to preserve compatibility with previous versions of the operating system. See the VSI OpenVMS Guide to System Security for further information about the C2 and B1 evaluated configurations. The following bits are defined: Bit Description 0 Obsolete. 1 Allows multiple user names to connect to DECW$SERVER. 2 Allows unevaluated DECwindows transports (such as TCP/IP). 3 Allows $SIGPRC and $PRCTERM to span job trees. 4 Allows security profile changes to protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT. 5 Allows creation of protected objects on a local node when the object server is absent and cannot update the cluster database VMS$OBJECTS.DAT. 6 Allows SPAWN or LIB$SPAWN commands in CAPTIVE accounts. 7 Reserved to VSI. 8 Reserved to VSI. 9 Disables password synchronizations among ACME agents on a systemwide pasis. This is functionally equivalent to the SYS$SINGLE_SIGNON logical name bit mask value 4 for LOGINOUT. 10 Allows privileged applications to successfully authenticate a user whose principal name maps to a SYSUAF record that is either expired or whose modal restrictions would otherwise prevent the account from being used. A SYSUAF record that is disabled or password-expired (in the case of traditional OpenVMS authentication) cannot be bypassed in this manner. An application with SECURITY privilege specifies the SYS$ACM ACME$M_NOAUTHORIZE function modifier to override authorization checks. 11 Allows any record in the SYSUAF file to be mapped using external authentication. 12 Allows intrusions on a clusterwide or local basis. (If the bit is cleared, intrusions are clusterwide.) 13 Reserved to VSI. 14 Allows the internal name and backlink of files and directories to be read if the user has either execute or read access to the file or directory. If this bit is clear, read access is required. Setting this bit allows the full POSIX pathname of a file or directory to be displayed when some of the directories in the path are execute-only to the user. This feature is required in the following environments: o POSIX pathnames are in use. o The BASH shell or other GNV components are in use. o Applications are using the realpath(), getcwd(), getpwnam(), and related C runtime library functions. The default value of 7 preserves compatibility with existing DECwindows Motif behavior. A value of 0 disables all unevaluated configurations. 2 SETTIME SETTIME enables (1) or disables (0) solicitation of the time of day each time the system is booted. This parameter should usually be off (0), so that the system sets the time of day at boot time to the value of the processor time-of-day register. You can reset the time after the system is up with the DCL command SET TIME (see the VSI OpenVMS DCL Dictionary). 2 SHADOW_D1-D5 Special DYNAMIC parameters reserved for VSI use. 2 SHADOW_ENABLE Special parameter reserved for VSI use. 2 SHADOWING SHADOWING loads the host-based volume shadowing driver. See VSI Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. Specify one of the following values: Value Description 0 No shadowing is enabled; SHDRIVER is not loaded. This is the default value. 2 Host-based volume shadowing enabled; SHDRIVER is loaded. Host-based volume shadowing provides shadowing of all disks located on a standalone system or an OpenVMS Cluster system. 2 SHADOW_HBMM_RTC (Alpha and Integrity servers) SHADOW_HBMM_RTC specifies, in seconds, how frequently each shadow set on this system has its modified block count compared with the reset threshold. If the modified block count exceeds the reset threshold, the bitmap for that shadow set is zeroed. This comparison is performed for all shadow sets mounted on the system that have HBMM bitmaps. The reset threshold is specified by the RESET_THRESHOLD keyword in the /POLICY qualifier of the SET SHADOW command. When the comparison is made, the modified block count might exceed the reset threshold by a small increment or by a much larger amount. The difference depends on the write activity to the volume and on the setting of this parameter. SHADOW_HBMM_RTC is a DYNAMIC parameter. 2 SHADOW_MAX_COPY The value of SHADOW_MAX_COPY controls how many parallel copy threads are allowed on a given node. Carefully consider the needs of each shadowed node when you set this parameter. Too high a value for SHADOW_MAX_COPY can affect performance by allowing too many copy threads to operate in parallel. Too low a value unnecessarily restricts the number of threads your system can effectively handle. See VSI Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. SHADOW_MAX_COPY has the AUTOGEN and DYNAMIC attributes. 2 SHADOW_MAX_UNIT SHADOW_MAX_UNIT specifies the maximum number of shadow sets that can exist on a system. The setting must be equal to or greater than the number of shadow sets you plan to have on a system. Dismounted shadow sets, unused shadow sets, and shadow sets with no write bitmaps allocated to them are included in the total. NOTE Review this default carefully. The setting must be equal to or greater than the number of shadow sets you plan to have on a system. If you attempt to mount more shadow sets than the number specified by SHADOW_MAX_UNIT, the MOUNT command will fail. Dismounted shadow sets, unused shadow sets, and shadow sets with no write bitmaps allocated to them are included in the count for SHADOW_MAX_UNIT. On Alpha and Integrity servers, the default value for this system parameter is 500, which consumes 24 KB of main memory. If you do not plan to use Volume Shadowing for OpenVMS, you can change the setting to its minimum of 10 (which consumes 480 bytes of main memory). Setting the default to its minimum frees up 23.5 KB of main memory on an OpenVMS Alpha or Integrity servers and 4.5 KB of main memory on a VAX system. (The maximum value of this parameter is 10,000.) This system parameter is not dynamic; that is, a reboot is required when you change the setting. 2 SHADOW_MBR_TMO SHADOW_MBR_TMO controls the amount of time the system tries to fail over physical members of a shadow set before removing them from the set. The SHADOW_MBR_TMO parameter replaces the temporary VMSD3 parameter used in prior releases. The SHADOW_MBR_TMO parameter is valid for use only with Phase II of Volume Shadowing for OpenVMS. You cannot set this parameter for use with Phase I, which is obsolete. Use the SHADOW_MBR_TMO parameter (a word) to specify the number of seconds, in decimal from 1 to 65,535, during which recovery of a repairable shadow set is attempted. If you do not specify a value or if you specify 0, the default delay of 120 seconds is used. Because SHADOW_MBR_TMO is a dynamic parameter, you should use the SYSGEN command WRITE CURRENT to permanently change its value. SHADOW_MBR_TMO is a DYNAMIC parameter. 2 SHADOW_PSM_RDLY When a copy or merge operation is needed on a shadow set that is mounted on more than one system, the shadowing driver attempts to perform the operation on a system that has a local connection to all the shadow set members. Shadowing implements the copy or merge operation by adding a time delay based on the number of shadow set members that are MSCP-served to the system. No delay is added for local members; a system with all locally accessible shadow set members usually performs the copy or merge before a system on which one or more members is served (and therefore is delayed) does. SHADOW_PSM_RDLY allows the system manager to adjust the delay that shadowing adds. By default, the delay is 30 seconds for each MSCP-served shadow set member. The valid range for the specified delay is 0 through 65,535 seconds. When a shadow set is mounted on a system, the value of SHADOW_ PSM_RDLY is used as the default shadow set member recovery delay for that shadow set. To modify SHADOW_PSM_RDLY for an existing shadow set, see the SET SHADOW/ /RECOVERY_OPTIONS=DELAY_PER_ SERVED_MEMBER=n command in VSI Volume Shadowing for OpenVMS. 2 SHADOW_REC_DLY (Alpha and Integrity servers) The value of the SHADOW_REC_DLY parameter specifies the length of time a system waits before it attempts to manage recovery operations on shadow sets that are mounted on the system. A shadow set is said to need recovery when a merge or copy operation is required on that shadow set. SHADOW_REC_DLY can be used to better predict which systems in an OpenVMS Cluster performs recovery operations. This is done by setting lower values of SHADOW_REC_DLY on systems that are preferred to handle recovery operations and higher values of SHADOW_REC_DLY on systems that are least preferred to handle recovery operations. The range of SHADOW_REC_DLY is 20 to 65535 seconds. The default value is 20 seconds. For more information about controlling which systems perform the merge or copy operations, see VSI Volume Shadowing for OpenVMS. SHADOW_REC_DLY is a DYNAMIC parameter. 2 SHADOW_SITE_ID (Alpha and Integrity servers) This parameter allows a system manager to define a site value, which Volume Shadowing uses to determine the best device to perform reads, thereby improving performance. The system manager can now define the site value to be used for all shadow sets mounted on a system. This parameter is an arbitrary numeric value coordinated by the system manager of disaster tolerant clusters. Reads from devices that have site values matching the shadow set's site value are preferred over reads from devices with different site values. For detailed information, see the description of the $SET DEVICE/SITE in the VSI OpenVMS DCL Dictionary and VSI Volume Shadowing for OpenVMS. SHADOW_SITE_ID is a DYNAMIC parameter. 2 SHADOW_SYS_DISK A SHADOW_SYS_DISK parameter value of 1 enables shadowing of the system disk. A value of 0 disables shadowing of the system disk. The default value is 0. Also specify a system disk shadow set virtual unit number with the SHADOW_SYS_UNIT system parameter, unless the desired system disk unit number is DSA0. A value of 4096 enables CI-based minimerge. To enable minimerge on a system disk, however, you must enable DOSD by setting the DUMPSTYLE parameter to dump off system disk, as described in the VSI OpenVMS System Manager's Manual. You can then add the value 4096 to your existing SHADOW_SYS_DISK value. For example, if you have SHADOW_SYS_DISK set to a value of 1, change it to 4097 to enable minimerge. 2 SHADOW_SYS_TMO The SHADOW_SYS_TMO parameter has the following two distinct uses: o At system boot time, when this is the first node in the cluster to boot and to create this specific shadow set. If the proposed shadow set is not currently mounted in the cluster, use this parameter to extend the time a booting system waits for all former members of the shadowed system disk to become available. o Once the system successfully mounts the virtual unit and begins normal operations. In this usage, the SHADOW_SYS_ TMO parameter controls the time the operating system waits for errant members of a system disk. (Use the SHADOW_MBR_TMO parameter to control the time the operating system waits for the errant members of an application disk.) This parameter applies only to members of the system disk shadow set. All nodes using a particular system disk shadow set should have their SHADOW_SYS_TMO parameter set to the same value once normal operations begin. The default value is 120 seconds. Change this parameter to a higher value if you want the system to wait more than the 120- second default for all members to join the shadow set. You can set the parameter value to 120 through 65,535 seconds. 2 SHADOW_SYS_UNIT Use this parameter for Phase II shadowing only. The SHADOW_SYS_ UNIT parameter is an integer value that contains the virtual unit number of the system disk. The default value is 0. The maximum value allowed is 9999. This parameter is effective only when the SHADOW_SYS_DISK parameter has a value of 1. This parameter should be set to the same value on all nodes booting off a particular system disk shadow set. See VSI Volume Shadowing for OpenVMS for more information about setting system parameters for volume shadowing. 2 SHADOW_SYS_WAIT The SHADOW_SYS_WAIT parameter extends the time a booting system waits for all current members of a mounted shadowed system disk to become available to this node. The shadow set must already be mounted by at least one other cluster node for this parameter to take effect. The default value is 480 seconds. Change this parameter to a higher value if you want the system to wait more than the 480- second default for all members to join the shadow set. You can set the parameter value to 1 through 65,535 seconds. 2 SMCI_FLAGS (Alpha Galaxy platforms only) The SMCI_FLAGS parameter controls operational aspects of SYS$PBDRIVER, the Galaxy Shared Memory Cluster Interconnect (SMCI). Bits in the bit mask are the following: Bit Mask Description 0 0 0 = Do not create local communications channels (SYSGEN default). Local SCS communications are primarily used in test situations and are not needed for normal operations. Not creating local communications saves resources and overhead. 1 = Create local communications channels. 1 2 0 = Load SYS$PBDRIVER if booting into both a Galaxy and a Cluster (SYSGEN Default). 1 = Load SYS$PBDRIVER if booting into a Galaxy. 2 4 0 = Minimal console output (SYSGEN default). 1 = Full console output; SYS$PBDRIVER displays console messages when it creates and tears down communications channels. SMCI_FLAGS has the DYNAMIC attribute. 2 SMCI_PORTS On systems running OpenVMS Galaxy software, the Shared Memory Cluster Interconnect (SMCI) system parameter SMCI_PORTS controls initial loading of SYS$PBDRIVER. This parameter is a bit mask; bits 0 through 25 each represent a controller letter. If bit 0 is set, which is the default setting, PBAx is loaded (where x represents the Galaxy Partition ID). If bit 1 is set, PBBx is loaded, and so on up to bit 25, which causes PBZx to be loaded. For OpenVMS Alpha Version 7.2 and later, VSI recommends leaving this parameter at the default value of 1. Loading additional ports allows multiple paths between Galaxy instances. In the initial release of the Galaxy software, having multiple communications channels is not an advantage because SYS$PBDRIVER does not support fast path. A future release of OpenVMS will provide Fast Path support for SYS$PBDRIVER, when multiple CPUs improve throughput by providing multiple communications channels between instances. 2 SMP_CPU_BITMAP This parameter indicates that the corresponding CPU is a bitmap representing up to 1024 CPUs. Each bit set in this bitmap indicates that the corresponding CPU automatically attempts to join the active set in an OpenVMS symmetric multiprocessing environment when the instance is booted. A cleared bit indicates that the corresponding CPU is ignored only at boot time; if it is otherwise viable, the CPU can be started at a later time. SMP_CPU_BITMAP defaults to all bits set. (CPU 0 through CPU 1023 are enabled for multiprocessing.) Note that the primary processor is always booted regardless of the setting of the corresponding bit in the CPU bitmap. To change the value of SMP_CPU_BITMAP in SYSBOOT or SYSGEN, specify a list of individual bits or contiguous groups of bits. For example: SYSGEN> SET SMP_CPU_BITMAP 0,5,17-21 The command in this example sets bits 0, 5, 17, 18, 19, 20, and 21 in the bitmap and clears all other bits. This parameter replaces the SMP_CPUS parameter. 2 SMP_LNGSPINWAIT SMP_LNGSPINWAIT establishes, in 10-microsecond intervals, the amount of time a CPU in an SMP system normally waits for access to a shared resource. This process is called spinwaiting. Generally spinlocks at IPL <= 8 have long holding times, therefore have their timeout intervals set to SMP_LNGSPINWAIT to prevent SPINWAIT timeouts in cases of nested acquisition. A timeout causes a CPUSPINWAIT bugcheck. The default value is 3000000 (30,00, 000 10-microsecond intervals or 30 second). 2 SMP_SANITY_CNT SMP_SANITY_CNT establishes, in 10-millisecond intervals, the timeout period for each CPU in a symmetric multiprocessing (SMP) system. Each CPU in an SMP system monitors the sanity timer of one other CPU in the configuration to detect hardware or software failures. If allowed to go undetected, these failures could cause the cluster to hang. A timeout causes a CPUSANITY bugcheck. The default value is 300 milliseconds (30 10-millisecond intervals). 2 SMP_SPINWAIT SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount of time a CPU in an SMP system normally waits for access to a shared resource. This process is called spinwaiting. A timeout causes a CPUSPINWAIT bugcheck. The default value is 100000 (100,000 10-microsecond intervals or 1 second). 2 SMP_TICK_CNT SMP_TICK_CNT sets the frequency of sanity timer checks by each CPU in a multiprocessing system. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SSI_ENABLE (Integrity servers only) This parameter controls the usage of system service interception. SSI_ENABLE is turned on by default. System Service Interception is a mechanism that allows user specified code to run before, after or instead of the intercepted system service. This mechanism is available on OpenVMS Alpha Version 6.1 and later and OpenVMS Integrity servers Version 8.3 and later, but the parameter SSI_ENABLE is relevant only on Integrity server systems. 2 SSINHIBIT SSINHIBIT controls whether system services are inhibited (1) (on a per-process basis). By default, system services are not inhibited (0). This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 STARTUP_P1-8 The following table describes possible values of STARTUP_P1 through _P8: STARTUP Value Description STARTUP_P1 Specifies the type of system boot the system- independent startup procedure is to perform when STARTUP_P1 has one of the following values: o " "- A full boot is performed. o "MIN"- A minimum boot that starts only what is absolutely necessary for the operating system to run. STARTUP_P2 Controls the setting of verification during the execution of the system-independent startup procedure, STARTUP.COM, when STARTUP_P2 has one of the values described in the lists below. STARTUP_P2 can be one of the values shown in the following list: o F[ALSE], N[O], 0, " "-Verification is not enabled; in other words, NOVERIFY is performed. o T[RUE], Y[ES], 1-Verification is enabled; in other words, a SET VERIFY is performed. Alternatively, STARTUP_P2 can be a string containing one or more of the letters shown in the following list: o C-Display various checkpointing messages during startup. o D-Log (or Dump) the output from the startup to a file called SYS$SPECIFIC:[SYSEXE]STARTUP.LOG. o P-DCL verification is enabled for each component file, but not for the startup driver. If both P and V are used, P is ignored. o V-Full DCL verification is enabled; same as TRUE. For more information about STARTUP_P2, see the SYSMAN command STARTUP SET OPTIONS. STARTUP_P3 Beginning in OpenVMS Version 7.2, if STARTUP_P3 is set to AGEN, the system executes AUTOGEN at the end of the startup sequence. STARTUP_P4 Reserved for future use. through STARTUP_P8 2 SWP_PRIO SWP_PRIO sets the priority of I/O transfers initiated by the swapper. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SWPFAIL SWPFAIL sets the number of consecutive swap failures allowed before the swap schedule algorithm is changed to ignore the swap quantum protection. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SWPOUTPGCNT This parameter allows the swapper an alternative mechanism before actually performing swaps. On Alpha and Integrity servers, SWPOUTPGCNT defines the minimum number of pagelets to which the swapper should attempt to reduce a process before swapping it out. The pagelets taken from the process are placed into the free-page list. SWPOUTPGCNT has the DYNAMIC attribute. On VAX systems, SWPOUTPGCNT also has the AUTOGEN attribute. 2 SWPRATE SWPRATE sets the swapping rate (in 10-millisecond units). This parameter limits the amount of disk bandwidth consumed by swapping. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SYSMWCNT SYSMWCNT sets the quota for the size of the system working set, which contains the pageable portions of the system, the paged dynamic pool, RMS, and the resident portion of the system message file. While a high value takes space away from user working sets, a low value can seriously impair system performance. Appropriate values vary, depending on the level of system use. When the system is running at full load, check the rate of system faults with the MONITOR PAGE command of the Monitor utility. An average system page fault rate of between 0 and 3 page faults per second is desirable. If the system page fault rate is high, and especially if the system seems to be slow, you should increase the value of SYSMWCNT. However, do not set this parameter so high that system page faulting never occurs. SYSMWCNT has the AUTOGEN, GEN, and MAJOR attributes. 2 SYSPFC SYSPFC sets the number of pages to be read from disk on each system paging operation. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 SYSSER_LOGGING (Alpha and Integrity servers) A value of 1 for SYSSER_LOGGING enables logging of system service requests for a process. The default is 1. SYSSER_LOGGING is a DYNAMIC system parameter. 2 SYSTEM_CHECK SYSTEM_CHECK investigates intermittent system failures by enabling a number of run-time consistency checks on system operation and recording some trace information. Enabling SYSTEM_CHECK causes the system to behave as if the following system parameter values are set (although the values of the following parameters are not actually changed): Parameter Value Description BUGCHECKFATAL 1 Crash the system on nonfatal bugchecks. POOLCHECK %X616400FF Enable all poolchecking, with an allocated pool pattern of %x61616161 ('aaaa') and deallocated pool pattern of x64646464 ('dddd'). MULTIPROCESSING 2 Enable full synchronization checking. While SYSTEM_CHECK is enabled, the previous settings of the BUGCHECKFATAL and MULTIPROCESSING parameters are ignored. However, setting the parameter POOLCHECK to a nonzero value overrides the setting imposed by SYSTEM_CHECK. Setting SYSTEM_CHECK creates certain image files that are capable of the additional system monitoring. These image files are located in SYS$LOADABLE_IMAGES and can be identified by the suffix _MON. For information about the type of data checking performed by SYSTEM_CHECK, see the description of the ACP_ DATACHECK parameter. For information about the performance implications of enabling SYSTEM_CHECK, see OpenVMS Performance Management. 2 TAPE_ALLOCLASS TAPE_ALLOCLASS determines the tape allocation class for the system. The tape allocation class creates a unique clusterwide device name for multiple access paths to the same tape. The TAPE_ALLOCLASS parameter can also be used to generate a unique clusterwide name for tape devices with identical unit numbers. 2 TAPE_MVTIMEOUT TAPE_MVTIMEOUT is the time in seconds that a mount verification attempt continues on a given magnetic tape volume. If the mount verification does not recover the volume within that time, the I/O operations outstanding to the volume terminate abnormally. TAPE_MVTIMEOUT is a DYNAMIC parameter. 2 TBSKIPWSL TBSKIPWSL specifies the maximum number of working set list entries that may be skipped while scanning for a "good" entry to discard. Setting this parameter to 0 disables skipping. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 TIME_CONTROL This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. TIME_CONTROL is an SMP bit mask parameter that controls debugging functions. The following bits are defined: Bit Description 0 Obsolete. 1 (EXE$V_SANITY) Disables the SMP sanity timer support. 2 (EXE$V_NOSPINWAIT) Disables the functional behavior of the SMP spinwait support. TIME_CONTROL is a DYNAMIC parameter. 2 TIMEPROMPTWAIT TIMEPROMPTWAIT defines the number of seconds that you want a processor to wait for the time and date to be entered when a system boot occurs, if the processor's time-of-year clock does not contain a valid time. (The time unit of micro-fortnights is approximated as seconds in the implementation.) If the time specified by TIMEPROMPTWAIT elapses, the system continues the boot operation, and the date and time are set to the last recorded time that the system booted. NOTE VSI recommends that you set the correct system time before allowing the system to run, so that all functions using time-stamping (such as the operator log, the error log, accounting records, file creation dates, and file expiration dates) contain correct time values. Depending on the value specified for the TIMEPROMPTWAIT parameter, the system acts in one of the following ways: o If TIMEPROMPTWAIT is 0, no prompt or wait occurs; the system boots immediately, using the time of the last boot as the system time. o If TIMEPROMPTWAIT is a positive number less than 32768, one prompt is issued and the value dictates how many seconds you can take to respond with a time. If you do not provide a time before TIMEPROMPTWAIT elapses, the system boots, using the time of the last boot as the system time. o If TIMEPROMPTWAIT is a number in the range of 32768 through 65535, the prompt for the time is issued at intervals starting with 2 and doubling until 256 seconds is reached. If no response is received, the prompts restart, with the 2-second interval. This prompting process repeats indefinitely, until you specify a time. 2 TIMVCFAIL TIMVCFAIL specifies the time required for an adapter or virtual circuit failure to be detected. VSI recommends that the default value be used. VSI also recommends that this value be lowered only in OpenVMS Cluster of three CPUs or less, that the same value be used on each computer in the cluster, and that dedicated LAN segments be used for cluster I/O. TIMVCFAIL is a DYNAMIC parameter. 2 TMSCP_LOAD TMSCP_LOAD allows the loading of the tape mass storage control protocol server software. The TMSCP_LOAD parameter also sets locally connected tapes served. For information about setting the TMSCP_LOAD parameter, see VSI OpenVMS Cluster Systems. Setting TMSCP_LOAD to 0 inhibits the loading of the tape server and the serving of local tapes. Setting TMSCP to 1 loads the tape server into memory at the time the system is booted and makes all directly connected tape drives available clusterwide. The following table describes the two states of the TMSCP_LOAD parameter: State Function 0 Do not load the TMSCP tape server. Do not serve any local tape devices clusterwide. This is the default value. 1 Load the TMSCP tape server. Serve all local TMSCP tape devices clusterwide. TMSCP_LOAD is an AUTOGEN parameter. 2 TMSCP_SERVE_ALL TMSCP_SERVE_ALL is a bit mask that controls the serving of tapes. The settings take effect when the system boots. You cannot change the settings when the system is running. Starting with OpenVMS Version 7.2, the serving types are implemented as a bit mask. To specify the type of serving your system will perform, locate the type you want in the following table and specify its value. For some systems, you may want to specify two serving types, such as serving all tapes except those whose allocation class does not match. To specify such a combination, add the values of each type, and specify the sum. In a mixed-version cluster that includes any systems running OpenVMS Version 7.1-x or earlier, serving all available tapes is restricted to serving all tapes except those whose allocation class does not match the system's allocation class (pre-Version 7.2 meaning). To specify this type of serving, use the value 9, which sets bit 0 and bit 3. The following table describes the serving type controlled by each bit and its decimal value: Value When Bit Set Description Bit 0 1 Serve all available tapes (locally attached and those connected to HSx and DSSI controllers). Tapes with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are also served if bit 3 is not set. Bit 1 2 Serve locally attached (non-HSx and non-DSSI) tapes. Bit 2 N/A Reserved. Bit 3 8 Restrict the serving specified by bit 0. All tapes except those with allocation classes that differ from the system's allocation class (set by the ALLOCLASS parameter) are served. This is pre-Version 7.2 behavior. If your cluster includes systems running OpenVMS Version 7.1-x or earlier, and you want to serve all available tapes, you must specify 9, the result of setting this bit and bit 0. Although the serving types are now implemented as a bit mask, the values of 0, 1, and 2, specified by bit 0 and bit 1, retain their original meanings: o 0 - Do not serve any tapes (the default for earlier versions of OpenVMS). o 1 - Serve all available tapes. o 2 - Serve only locally attached (non-HSx and non-DSSI) tapes. If the TMSCP_LOAD system parameter is 0, TMSCP_SERVE_ALL is ignored. 2 TTY_ALTALARM TTY_ALTALARM sets the size of the alternate type-ahead buffer alarm. This value indicates at what point an XOFF should be sent to terminals that use the alternate type-ahead buffers with the size specified by the TTY_ALTYPAHD parameter. 2 TTY_ALTYPAHD TTY_ALTYPAHD sets the size of the alternate type-ahead buffer. Use this parameter to allow the block mode terminals and communications lines to operate more efficiently. The default value is usually adequate. Do not exceed the maximum value of 32767 when setting this parameter. 2 TTY_AUTOCHAR TTY_AUTOCHAR sets the character the terminal driver echoes when the job controller has been notified. TTY_AUTOCHAR is a DYNAMIC parameter. 2 TTY_BUF TTY_BUF sets the default line width for terminals. 2 TTY_CLASSNAME TTY_CLASSNAME provides the 2-character prefix for the terminal class driver name that is required when booting. Changing the prefix can be useful when debugging a new terminal driver. 2 TTY_DEFCHAR TTY_DEFCHAR sets the default characteristics for terminals, using a code derived by summing the following hexadecimal values: Characteristic Value (Hex) Function PASSALL 1 Passall. NOECHO 2 Noecho mode. NOTYPEAHEAD 4 No type-ahead buffer. ESCAPE 8 Escape sequence processing. HOSTSYNC 10 Host can send XON and XOFF. TTSYNC 20 Terminal can send XON and XOFF. SCRIPT 40 Internal use only. LOWER 80 Lowercase. MECHTAB 100 Mechanical tabs. WRAP 200 Wraparound at end of line. CRFILL 400 Perform carriage return fill. LFFILL 800 Perform line feed fill. SCOPE 1000 Terminal is a scope. REMOTE 2000 Internal use only. EIGHTBIT 8000 Eight-bit terminal. MBXDSABL 10000 Disable mailbox. NOBRDCST 20000 Prohibit broadcast. READSYNC 40000 XON and XOFF on reads. MECHFORM 80000 Mechanical form feeds. HALFDUP 100000 Set for half-duplex operation. MODEM 200000 Set for modem signals. PAGE FF000000 Page size. Default is 24. Do not set the CRFILL or LRFILL characteristic as the default in TTY_DEFCHAR. Where a condition is false, the value is 0. The upper byte is the page length. The default characteristics are 24 lines per page, terminal synchronization, wraparound, lowercase, scope, and full-duplex. 2 TTY_DEFCHAR2 TTY_DEFCHAR2 sets a second longword of default terminal characteristics. The default characteristics are represented as a code that is derived by summing the following hexadecimal values: Characteristic Value (Hex) Function LOCALECHO 1 Enable local echo terminal logic; use with the TTY_DEFCHAR NOECHO characteristic. AUTOBAUD 2 Enable autobaud detection. HANGUP 4 Hang up on logout. MODHANGUP 8 Allow modification of HANGUP without privileges. BRDCSTMBX 10 Allow sending of broadcasts to mailboxes. XON 20 (No effect in this parameter.) DMA 40 (No effect in this parameter.) ALTYPEAHD 80 Use the alternate type-ahead parameters. SETSPEED 100 Clear to allow setting of speed without privileges. DCL_MAILBX 200 Function reserved for VSI use only. DECCRT4 400 Terminal is DIGITAL CRT Level 4. COMMSYNC 800 Enable flow control using modem signals. EDITING 1000 Line editing allowed. INSERT 2000 Sets default mode for insert. FALLBACK 4000 Do not set this bit with SYSGEN. DIALUP 8000 Terminal is a dialup line. SECURE 10000 Guarantees that no process is connected to terminal after Break key is pressed. DISCONNECT 20000 Allows terminal disconnect when a hangup occurs. PASTHRU 40000 Terminal is in PASTHRU mode. SYSPWD 80000 Log in with system password only. SIXEL 100000 Sixel graphics. DRCS 200000 Terminal supports loadable character fonts. PRINTER 400000 Terminal has printer port. APP_KEYPAD 800000 Notifies application programs of state to set keypad on exit. ANSICRT 1000000 Terminal conforms to ANSI CRT programming standards. REGIS 2000000 Terminal has REGIS CRT capabilities. BLOCK 4000000 Block mode terminal. AVO 8000000 Terminal has advanced video. EDIT 10000000 Terminal has local edit capabilities. DECCRT 20000000 Terminal is a DIGITAL CRT. DECCRT2 40000000 Terminal is a DIGITAL CRT Level 2. DECCRT3 80000000 Terminal is a DIGITAL CRT Level 3. The defaults are AUTOBAUD and EDITING. 2 TTY_DEFCHAR3 (Alpha and Integrity servers) TTY_DEFCHAR3 allows a user to set a bit so that the OpenVMS terminal driver remaps CTRL/H to Delete. VSI recommends that you not set this bit as a systemwide default. Characteristic Value (Hex) Function TT3$M_BS 10 When this bit is set, the OpenVMS terminal console remaps CTRL/H to Delete. For more information, see the SET TERM and SHOW TERM commands in the VSI OpenVMS DCL Dictionary. 2 TTY_DEFPORT TTY_DEFPORT provides flag bits for port drivers. Bit 0 set to 1 indicates that the terminal controller does not provide automatic XON/XOFF flow control. This bit should not be set for VSI Controllers, but it is needed for some foreign controllers. Currently only the YCDRIVER (DMF32, DMZ32) uses this bit. The remaining bits are reserved for future use. This special parameter should be modified only if recommended by VSI. 2 TTY_DIALTYPE TTY_DIALTYPE provides flag bits for dialups. Bit 0 is 1 for United Kingdom dialups and 0 for all others. Bit 1 controls the modem protocol used. Bit 2 controls whether a modem line hangs up 30 seconds after seeing CARRIER if a channel is not assigned to the device. The remaining bits are reserved for future use. See the OpenVMS I/O User's Reference Manual for more information about flag bits. 2 TTY_DMASIZE TTY_DMASIZE specifies a number of characters in the output buffer. Below this number, character transfers are performed; above this number, DMA transfers occur if the controller is capable of DMA I/O. TTY_DMASIZE is a DYNAMIC parameter. 2 TTY_PARITY TTY_PARITY sets terminal default parity. 2 TTY_RSPEED TTY_RSPEED defines the receive speed for terminals. If TTY_ RSPEED is 0, TTY_SPEED controls both the transmit and the receive speed. Maximum value is 20. This parameter is only applicable for controllers that support split-speed operations, such as the DZ32 and the DMF32. 2 TTY_SCANDELTA TTY_SCANDELTA sets the interval for polling terminals for dialup and hangup events. Shorter intervals use more processor time; longer intervals may result in missing a hangup event. 2 TTY_SILOTIME TTY_SILOTIME defines the interval at which the DMF32 hardware polls the input silo for received characters. The DMF32 asynchronous terminal controller can delay the generation of a single input interrupt until multiple characters have accumulated in the input silo. TTY_SILOTIME specifies the number of milliseconds that the characters are allowed to accumulate prior to the generation of an input interrupt by the hardware. NOTE The remainder of this discussion is of interest to customers who use Digi Edgeport hardware. TTY_SILOTIME controls latency, trading throughput and system overhead for latency. The default value for TTY_SILOTIME is 8. This value is multiplied by 100 and is used as a count of the number of times to send a query to the device for more data after a character transmit or receive is performed. If no input (or no subsequent output) is seen after 800 responses to the query, the driver stops sending queries to the device and waits for an input interrupt. Reducing the TTY_SILOTIME value allows the device to buffer more data, with slightly higher latency. Increasing the value of TTY_SILOTIME makes the device more sensitive to latency but decreases buffering and overall throughput; it also adds more system and USB overhead. Setting TTY_SILOTIME to zero causes the driver to send input queries to the device continually. This setting causes the lowest latency, the highest system overhead, and the lowest throughput possible. 2 TTY_SPEED TTY_SPEED sets the systemwide default speed for terminals. Low byte is transmit speed, and high byte is receive speed. If high byte is set to 0, receive speed is identical to transmit speed. Maximum value is 20. Baud rates are defined by the $TTDEF macro. 2 TTY_TIMEOUT TTY_TIMEOUT sets the number of seconds before a process associated with a disconnected terminal is deleted. The default value (900 seconds) is usually adequate. Note that using values for TTY_TIMEOUT greater than one year (value %X01E13380) can cause overflow errors and result in a disconnected device timing out immediately. TTY_TIMEOUT is a DYNAMIC parameter. 2 TTY_TYPAHDSZ TTY_TYPAHDSZ sets the size of the terminal type-ahead buffer. The default value is usually adequate. Do not exceed the maximum value of 32767 when setting this parameter. 2 UAFALTERNATE UAFALTERNATE enables or disables the assignment of SYSUAF as the logical name for SYSUAFALT, causing all references to the user authorization file (SYSUAF) to be translated to SYS$SYSTEM:SYSUAFALT. Use of the normal user authorization file (SYS$SYSTEM:SYSUAF) can be restored by deassigning the system logical name SYSUAF. This parameter should be set on (1) only when the system is being used by a restricted set of users. You must create a user authorization file named SYSUAFALT prior to setting UAFALTERNATE to 1. UAFALTERNATE has the GEN and MAJOR attributes. 2 USERD1 USERD1 is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USERD1. On Alpha and Integrity servers, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. USERD1 is a DYNAMIC parameter. 2 USERD2 USERD2 is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USERD2. On Alpha and Integrity servers, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. USERD2 is a DYNAMIC parameter. 2 USER3 USER3 is a parameter that is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USER3. On Alpha and Integrity servers, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. 2 USER4 USER4 is a parameter that is reserved for definition at the user's site. The reserved longword is referenced by the symbol SGN$GL_USER4. On Alpha and Integrity servers, this symbol is in the SYS$LOADABLE_IMAGES:SYS$BASE_IMAGE module. 2 VAXCLUSTER VAXCLUSTER controls loading of the cluster code. Specify one of the following: Value Description 0 Never form or join a cluster. 1 Base decision of whether to form (or join) a cluster or to operate standalone on the presence of cluster hardware. 2 Always form or join a cluster. The default value is 1. VAXCLUSTER is an AUTOGEN parameter. 2 VCC_FLAGS (Alpha only) The static system parameter VCC_FLAGS enables and disables file system data caching. If caching is enabled, VCC_ FLAGS controls which file system data cache is loaded during system startup. Value Description 0 Disables file system data caching on the local node and throughout the OpenVMS Cluster. In an OpenVMS Cluster, if caching is disabled on any node, none of the other nodes can use the extended file cache or the virtual I/O cache. They can't cache any file data until that node either leaves the cluster or reboots with VCC_FLAGS set to a nonzero value. 1 Enables file system data caching and selects the Virtual I/O Cache. This is the default for VAX systems. 2 Enables file system data caching and selects the extended file cache. This is the default for Alpha systems. NOTE On Integrity servers, the volume caching product ([SYS$LDR]SYS$VCC.EXE) is not available. XFC caching is the default caching mechanism. Setting the VCC_FLAGS parameter to 1 is equivalent to not loading caching at all or to setting VCC_FLAGS to 0. VCC_FLAGS is an AUTOGEN parameter. 2 VCC_MAXSIZE (Alpha and Integrity servers) The static system parameter VCC_ MAXSIZE controls the size of the virtual I/O cache. VCC_MAXSIZE, which specifies the size in blocks, is 3,700,000 by default. The virtual I/O cache cannot shrink or grow. Its size is fixed at system startup. To adjust the XFC size, use the VCC_MAX_CACHE system parameter. VCC_MAXSIZE is an AUTOGEN parameter. 2 VCC_MAX_CACHE (Alpha and Integrity servers) The dynamic system parameter VCC_ MAX_CACHE controls the maximum size of the extended file cache. It specifies the size in megabytes. By default, VCC_MAX_CACHE has a special value of -1 for people who do not want to tune their systems manually; this value means that at system startup, the maximum size of the extended file cache is set to 50 percent of the physical memory on the system. The extended file cache can automatically shrink and grow, depending on your I/O workload and how much spare memory your system has. As your I/O workload increases, the cache automatically grows, but never to more than the maximum size. When your application needs memory, the cache automatically shrinks. The value of VCC_MAX_CACHE at system startup sets an upper limit for the maximum size of the extended file cache. You cannot increase the maximum size of VCC_MAX_CACHE beyond its value at boot time. For example, if VCC_MAX_CACHE is 60 MB at system startup, you can then set VCC_MAX_CACHE to 40, which decreases the maximum size to 40 MB. If you then set VCC_MAX_CACHE to 80, the maximum size is only increased to 60 MB, the value set at system startup. Note that VCC_MAX_CACHE is a semi-dynamic parameter. If you change its value, you must enter the DCL command SET CACHE/RESET for any changes to take effect immediately. Otherwise, it might take much more time for the changes to take effect. If you are using the reserved memory registry to allocate memory permanently, you must set the VCC$MIN_CACHE_SIZE entry in the reserved memory registry to a value less than or equal to VCC_MAX_CACHE at system startup time. For instructions on setting permanent memory allocations for the cache, see the VSI OpenVMS System Manager's Manual. VCC_MAX_CACHE is a DYNAMIC parameter. 2 VCC_MAX_IO_SIZE (Alpha and Integrity servers) The dynamic system parameter VCC_ MAX_IO_SIZE controls the maximum size of I/O that can be cached by the extended file cache. It specifies the size in blocks. By default, the size is 127 blocks. Changing the value of VCC_MAX_IO_SIZE affects reads and writes to volumes currently mounted on the local node, as well as reads and writes to volumes mounted in the future. If VCC_MAX_IO_SIZE is 0, the extended file cache on the local node cannot cache any reads or writes. However, the system is not prevented from reserving memory for the extended file cache during startup if a VCC$MIN_CACHE_SIZE entry is in the reserved memory registry. VCC_MAX_IO_SIZE is a DYNAMIC parameter. 2 VCC_MAX_LOCKS (Alpha and Integrity servers) VCC_MAX_LOCKS is a special parameter reserved for VSI use only. Extended file cache will use this parameter in future versions. 2 VCC_PAGESIZE (Alpha and Integrity servers) VCC_PAGESIZE is a special parameter reserved for VSI use only. Extended file cache will use this parameter in future versions. 2 VCC_READAHEAD (Alpha and Integrity servers) The dynamic system parameter VCC_ READAHEAD controls whether the extended file cache can use read- ahead caching. Read-ahead caching is a technique that improves the performance of applications that read data sequentially. By default VCC_READAHEAD is 1, which means that the extended file cache can use read-ahead caching. The extended file cache detects when a file is being read sequentially in equal-sized I/Os, and fetches data ahead of the current read, so that the next read instruction can be satisfied from cache. To stop the extended file cache from using read-ahead caching, set VCC_READAHEAD to 0. Changing the value of VCC_READAHEAD affects volumes currently mounted on the local node, as well as volumes mounted in the future. Readahead I/Os are totally asynchronous from user I/Os and only take place if sufficient system resources are available. VCC_READAHEAD is a DYNAMIC parameter. 2 VCC_RSVD (Alpha and Integrity servers) VCC_RSVD is a special parameter reserved for VSI use only. Extended file cache will use this parameter in future versions. 2 VCC_WRITEBEHIND (Alpha and Integrity servers) VCC_WRITEBEHIND is reserved for VSI use only. Extended file cache will use this parameter in future versions. 2 VCC_WRITE_DELAY (Alpha and Integrity servers) VCC_WRITE_DELAY is reserved for VSI use only. 2 VHPT_SIZE (Integrity servers only) VHPT_SIZE is the number of kilobytes to allocate for the virtual hash page table (VHPT) on each CPU in the system: o 0 indicates that no VHPT is allocated. o 1 indicates that OpenVMS is to choose a default size that is appropriate for your system configuration. If a VHPT is created, the smallest size is 32KB. The VHPT_SIZE must be a power of 2 KB in size. If the number specified is not a power of 2, OpenVMS chooses a VHPT size to use for your system that is close to the number specified. If insufficient memory is available during system startup, OpenVMS might choose a smaller size for the VHPT of each CPU. A summary of possible values for VHPT_SIZE is in the following table: Value Description 0 Do not create a VHPT on each CPU. 1 (default) OpenVMS chooses a VHPT of an appropriate size for each CPU. n Create a VHPT of nKB for each CPU, where n is a power of 2 that is 32 or greater. (The maximum value, however, is platform-dependent.) 2 VIRTUALPAGECNT On VAX systems, VIRTUALPAGECNT sets the maximum number of virtual pages that can be mapped for any one process. A program is allowed to divide its virtual space between the P0 and P1 tables in any proportion. If you use SYS$UPDATE:LIBDECOMP.COM to decompress libraries and the VIRTUALPAGECNT setting is low, make sure you set the PGFLQUOTA field in the user authorization file to at least twice the size of the library. At installation time, AUTOGEN automatically sets an appropriate value for VIRTUALPAGECNT. The value depends on the particular configuration-the type and number of graphics adapters on the system, if any exist. You cannot set VIRTUALPAGECNT below the minimum value required for your graphics configuration. Because the VIRTUALPAGECNT setting supports hardware address space rather than system memory, do not use the value of VIRTUALPAGECNT that AUTOGEN sets to gauge the size of your page file. Starting with OpenVMS Version 7.0, VIRTUALPAGECNT has been an obsolete parameter on Alpha systems. Note, however, that the parameter remains in existence on Alpha and Integrity servers for compatibility purposes and has a default and maximum value of %X7FFFFFFF. SYSBOOT and AUTOGEN enforce this default value. VIRTUALPAGECNT has the AUTOGEN, GEN, and MAJOR attributes. 2 VMS1-8 VMSD1, VMSD2, VMSD3, VMSD4, VMS5, VMS6, VMS7, and VMS8 are special parameters reserved for VSI use. VMSD1 through VMSD4 are DYNAMIC. 2 VOTES VOTES establishes the number of votes an OpenVMS Cluster member system contributes to a quorum. VOTES has the AUTOGEN attribute. 2 WBM_MSG_INT WBM_MSG_INT is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_UPPER and WBM_MSG_LOWER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. In single-message mode, WBM_MSG_INT is the time interval in milliseconds between assessments of the most suitable write bitmap message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered-message mode. In buffered-message mode, WBM_MSG_INT is the maximum time a message waits before it is sent. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message. During periods of increased message traffic, grouping multiple messages to send in one SCS message to the master write bitmap is generally more efficient than sending each message separately. The minimum value of WBM_MSG_INT is 10 milliseconds. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10 milliseconds. WBM_MSG_INT is a DYNAMIC parameter. 2 WBM_MSG_LOWER WBM_MSG_LOWER is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_ UPPER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. WBM_MSG_LOWER is the lower threshold for the number of messages sent during the test interval that initiates single-message mode. In single-message mode, the writes issued by each remote node are, by default, sent one by one in individual SCS messages to the node with the master write bitmap. If the writes sent by a remote node reach an upper threshhold of messages during a specified interval, single-message mode switches to buffered- message mode. The minimum value of WBM_MSG_LOWER is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 10. WBM_MSG_LOWER is a DYNAMIC parameter. 2 WBM_MSG_UPPER WBM_MSG_UPPER is one of three system parameters that are available for managing the update traffic between a master write bitmap and its corresponding local write bitmaps in an OpenVMS Cluster system. The others are WBM_MSG_INT and WBM_MSG_ LOWER. These parameters set the interval at which the frequency of sending messages is tested and also set an upper and lower threshold that determine whether the messages are grouped into one SCS message or are sent one by one. WBM_MSG_UPPER is the upper threshold for the number of messages sent during the test interval that initiates buffered-message mode. In buffered-message mode, the messages are collected for a specified interval and then sent in one SCS message. The minimum value of WBM_MSG_UPPER is 0 messages per interval. The maximum value is -1, which corresponds to the maximum positive value that a longword can represent. The default is 100 seconds. WBM_MSG_UPPER is a DYNAMIC parameter. 2 WBM_OPCOM_LVL WBM_OPCOM_LVL controls whether write bitmap system messages are sent to the operator console. Possible values are shown in the following table: Value Description 0 Messages are turned off. 1 The default; messages are provided when write bitmaps are started, deleted, and renamed, and when the SCS message mode (buffered or single) changes. 2 All messages for a setting of 1 are provided plus many more. WBM_OPCOM_LVL is a DYNAMIC parameter. 2 WINDOW_SYSTEM WINDOW_SYSTEM specifies the windowing system to be used on a workstation. Specify one of the following values: Value Description 1 Load the DECwindows Motif for OpenVMS workstation environment. 2 Load the UIS workstation environment. WINDOW_SYSTEM is a DYNAMIC parameter. 2 WLKSYSDSK (Alpha and Integrity servers) WLKSYSDSK is used by various bootstrap components to determine if the system disk should be treated as though it is write-locked. This parameter is used primarily to allow OpenVMS to boot from a CD. 2 WPRE_SIZE WPRE_SIZE represents the number of pages to be allocated to accommodate WatchPoint Recovery Entries (WPRE) on the Watchpoint Driver. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. WPRE_SIZE is a DYNAMIC parameter. 2 WPTTE_SIZE WPTTE_SIZE is the number of entries that the WPDRIVER creates in the WatchPoint Trace Table. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. WPTTE_SIZE is a DYNAMIC parameter. 2 WRITABLESYS WRITABLESYS controls whether system code is writable. This parameter is set (value of 1) for debugging purposes only. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 WRITESYSPARAMS On Alpha and Integrity servers, WRITESYSPARAMS indicates that parameters are modified during SYSBOOT and are written out to ALPHAVMSSYS.PAR by STARTUP.COM. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. WRITESYSPARAMS is a DYNAMIC parameter. 2 WSDEC Increasing the value of this parameter tends to increase the speed with which working set limits are decreased when the need arises. On Alpha and Integrity servers, WSDEC specifies the number of pagelets by which the limit of a working set is automatically decreased at each adjustment interval (which is quantum end). At a setting of 35, for example, the system decreases the limit of a working set by 35 pagelets each time a decrease is required. WSDEC has the AUTOGEN, DYNAMIC, and MAJOR attributes. 2 WSINC Decreasing the value of this parameter tends to reduce the speed with which working set limits are increased when the need arises. Normally, you should keep this parameter at a high value because a rapid increase in limit is often critical to performance. On Alpha and Integrity servers, WSINC specifies the number of pagelets by which the limit of a working set is automatically increased at each adjustment interval (which is quantum end). At a setting of 150, for example, the system increases the limit of a working set by 150 pagelets each time an increase is required. On Alpha and Integrity servers, the default value is 2400 512- byte pagelets (150 8192-byte Alpha and Integrity server pages). A value of 0 for WSINC disables the automatic adjustment of working set limits for all processes. Limits stay at their base values. You can disable the automatic adjustment of working set limits on a per-process basis by using the DCL command SET WORKING_SET. WSINC has the DYNAMIC and MAJOR attributes. On Alpha and Integrity servers, WSINC also has the AUTOGEN attribute. 2 WSMAX WSMAX sets the maximum number of pages on a systemwide basis for any working set. WSMAX is calculated by AUTOGEN as a quarter of the first gigabyte plus a decreasing amount for each additional gigabyte up to a maximum value of 3002368 pagelets, like so: Memory WSMAX 512 MB 262144 1 GB 524288 2 GB 768432 4 GB 1091584 8 GB 1421312 16 GB 1763328 32 GB 2105344 64 GB 2435072 128 GB 2740224 256+ GB 3002368 Note: Reserved memory is excluded. WSMAX units are pagelets. This is intended to assist managers of systems that host large numbers of users whose working sets are not large. Systems whose user bases consist of a small number of users (or processes) that require large amounts of physical memory (for example, simulations) might need to set MIN_WSMAX to a value that satisfies the requirements of those processes. WSMAX has the AUTOGEN, GEN, and MAJOR attributes. 2 XQPCTL2 XQPCTL2 controls improved concurrency. The default value of XQPCTL2 is 1, which turns on improved concurrency. Setting XQPCTL2 to 0 turns off improved concurrency. This parameter affects local access to the extent and file ID caches. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 XQPCTLD1 XQPCTLD1 controls multithreading, which can be used only by PATHWORKS servers. The default value of XQPCTLD1 is 8, which enables multithreading. Setting XQPCTLD1 to 0 disables multithreading, This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. 2 ZERO_LIST_HI (Alpha and Integrity servers) ZERO_LIST_HI is the maximum number of pages zeroed and put on the zeroed page list. This list is used as a cache of pages containing all zeros, which improves the performance of allocating such pages. ZERO_LIST_HI has the AUTOGEN and DYNAMIC attributes. ! ********************************************************************* ! PARAM-END! PARAM-INSERT ! HELP on the individual parameters is taken from SYSGEN and ! is inserted here by the build procedures. Please do not edit the ! first comment line. !*****************************************************************