Changes the characteristics of one or more mounted Files-11
volumes. The SET VOLUME command affects only the node on which
the command is issued, and will not affect any other nodes, even
when a volume is mounted on multiple nodes in an OpenVMS Cluster
configuration.
If you are not the owner of the volume, requires control access
to the volume.
Format
SET VOLUME device-name[:][,...]
1 – Parameter
device-name[:][,...]
Specifies the name of one or more mounted Files-11 volumes.
2 – Qualifiers
2.1 /ACCESSED
/ACCESSED[=n]
Requires OPER (operator) privilege.
Specifies the number of directories to be maintained in system
space for ready access. You can specify a value n in the range
of 0 to 255. If you specify the qualifier /ACCESSED and omit
the number of directories, a default value of 3 is used. If you
specify a value greater than the current value, the new value is
effective immediately; otherwise, the new value is not effective
until the next time the volume is mounted.
2.2 /CACHE
/CACHE=(option[,...])
Enables or disables XFC caching for the volume. If CLEAR_DATA
option is specified, then contents of the volume already in cache
are cleared. (If you do not specify the /CACHE qualifier, XFC
caching attributes of the volume as well as the contents of
the volume already in cache are not affected.) Keywords are as
follows:
Keyword Description
DATA Enables XFC caching for the volume.
[NO]DATA Disables XFC caching for the volume.
CLEAR_DATA Clears contents of the volume present in the XFC
cache (if any).
2.3 /DATA_CHECK
/DATA_CHECK[=(option[,...])]
Defines a default for data check operations following all read
and write operations to the specified volume. (If you do not
specify the /DATA_CHECK qualifier, no checks are made.) Keywords
are as follows:
[NO]READPerforms checks following all read operations.
[NO]WRITPerforms checks following all write operations (default).
2.4 /ERASE_ON_DELETE
/ERASE_ON_DELETE
/NOERASE_ON_DELETE (default)
Determines whether the space occupied by a file is overwritten
with a system-specified pattern when a file on the volume is
deleted.
2.5 /EXTENSION
/EXTENSION[=n]
Specifies the number of blocks to be used as a default extension
size for all files on the volume. You can specify a value n in
the range of 0 to 65,535. If you specify the /EXTENSION qualifier
without specifying a value, a default value of 0 (the OpenVMS RMS
default) is used.
For example, during an update operation, the extension default
is used when a file increases to a size greater than its initial
default allocation.
2.6 /FILE_PROTECTION
/FILE_PROTECTION=(ownership[:access][,...])
Sets the default protection to be applied to all files on the
specified disk volume. Specify the ownership parameter as system
(S), owner (O), group (G), or world (W) and the access parameter
as read (R), write (W), execute (E), or delete (D). A null access
specification means no access.
NOTE
This attribute is not used while the volume is in use on an
OpenVMS system, but the attribute is provided to control
the process use of the volume on RSX-11M systems. The
OpenVMS system always uses the default file protection;
the protection can be changed with the DCL command SET
PROTECTION/DEFAULT.
2.7 /HIGHWATER_MARKING
/HIGHWATER_MARKING
/NOHIGHWATER_MARKING
Determines whether the file highwater mark (FHM) volume attribute
is set. The FHM attribute guarantees that a user cannot read data
that was not written by the user. Applies to Files-11 On-Disk
Structure Level 2 (ODS-2) and 5 (ODS-5) volumes only.
2.8 /LABEL
/LABEL=volume-label
Specifies a 1- to 12-character ANSI name to be encoded on the
volume. The specified label remains in effect until it is changed
explicitly; dismounting the volume does not affect the label. VSI
strongly recommends that a volume label should consist of only
alphanumeric characters, dollar signs ($), underscores (_), and
hyphens (-).
NOTE
Changing the volume label does not change other structures
that used the original volume label. For example, the
DISK$label logical volume name is not changed nor is the
device-lock name that is kept internally by OpenVMS. As a
result, if you attempt to access another disk that has the
same volume label as the original volume of this device,
you may get error messages such as the following: "%MOUNT-F-
VOLALRMNT, another volume of same label already mounted".
VSI recommends that, if you change a disk volume label,
you also dismount and remount the disk on all nodes in the
cluster so that the names and locks are consistent.
If you change the volume label on a nonsystem disk and the
PRODUCT INSTALL command has been used to install software
products on that disk, you must update the software product
database to reflect this change. To accomplish this, first
dismount and remount the disk. Then use the PRODUCT REGISTER
VOLUME command to replace all occurrences of the old DISK$label
with the new logical volume name that was created by the MOUNT
command.
NOTE
You do not need to take this action when you change
the label of the system disk. The POLYCENTER Software
Installation Utility continues to use the old logical
volume name until the system is rebooted. After reboot (when
the system disk is remounted), the utility automatically
identifies the system disk using its new logical volume
name.
2.9 /LIMIT
/LIMIT[=n]
Specifies that the volume is to be enabled for volume expansion.
n specifies the upper limit of the expansion (in blocks). If no
value is specified, the maximum expansion potential is set up.
The maximum expansion size depends on the cluster size defined
for the volume using the INITIALIZE/CLUSTER_SIZE command. If
the cluster size is 8 or more, the current maximum expansion
supported on OpenVMS (1TB) is set up. If the cluster size is less
than 8, the expansion limit is set to 65535*4096*Cluster-size
because the maximum size of the bitmap is 65535 blocks. For more
information about volume expansion, see the VSI Volume Shadowing
for OpenVMS manual.
This command must be executed while the disk is mounted
privately.
If you add additional physical storage in the future, you can use
the /SIZE qualifier to increase the volume size.
2.10 /LOG
/LOG
/NOLOG (default)
Determines whether the volume specification of each volume is
displayed after the modification.
2.11 /MOUNT_VERIFICATION
/MOUNT_VERIFICATION
/NOMOUNT_VERIFICATION
Determines whether mount verification is enabled. Mount
verification prevents interruption to user input/output
operations and notifies the operator of problems with the disk.
2.12 /OWNER_UIC
/OWNER_UIC[=uic]
Sets the owner user identification code (UIC) of the volume
to the specified UIC. The default UIC is that of the current
process. Brackets ([]) are required around the UIC. Specify the
UIC by using standard UIC format as described in the VSI OpenVMS
Guide to System Security.
2.13 /PROTECTION
/PROTECTION=(ownership[:access][,...])
Specifies the protection to be applied to the volume. The
following rules apply:
o Specify the ownership parameter as system (S), owner (O),
group (G), or world (W).
o Specify the access parameter as read (R), write (W), create
(C), or delete (D).
The default protection is all types of access by all categories
of user.
2.14 /REBUILD
/REBUILD[=FORCE]
Recovers caching limits for a volume that was dismounted
improperly. If a disk volume was dismounted improperly (such
as during a system failure), and was then remounted with the
MOUNT/NOREBUILD command, you can use SET VOLUME/REBUILD to
recover the caching that was in effect at the time of the
dismount. The FORCE option forces the disk to be rebuilt
unconditionally, thus updating the free block count in the disk
volume's lock value block.
2.15 /RETENTION
/RETENTION=(min[,max])
Specifies the minimum and maximum retention times to be used by
the file system to determine the expiration date for files on
the volume. When a file is created, its expiration date is set
to the current time plus the maximum time. Each time the file is
accessed, the current time is added to the minimum time. If the
sum is greater than the expiration date, a new expiration date is
computed.
If you omit the maximum value, a default value that
is the smaller of (2 x min) or (min + 7) days is
used. For example, /RETENTION=3- is the same as
/RETENTION=(3-,6-), while /RETENTION=10- is the same as
/RETENTION=(10-,17-).
The command SET VOLUME/RETENTION=0 disables retention times on
the volume.
2.16 /SIZE
/SIZE[=nnn]
Specifies the amount of disk space (in blocks) that is usable for
the file system. This value must be greater than the current
logical volume size and less than or equal to the physical
size of the disk or the expansion limit (specified by /LIMIT),
whichever is smaller.
If the value is omitted, the usable space is increased to the
physical size of the disk or the expansion limit, whichever is
smaller.
2.17 /STRUCTURE_LEVEL
/STRUCTURE_LEVEL=n
Sets the structure level of the volume. Use the value 5 to set
the volume to ODS-5.
When the /STRUCTURE_LEVEL qualifier is used with other
qualifiers, the volume structure level is set prior to the other
qualifiers being performed.
You cannot use the SET VOLUME command to change a volume from
ODS-5 to ODS-2. To reset a volume to ODS-2, see the instructions
in the VSI OpenVMS System Manager's Manual, Volume 1: Essentials.
2.18 /SUBSYSTEM
/SUBSYSTEM
/NOSUBSYSTEM
Enables the processing of subsystem ACEs. Requires the SECURITY
privilege. By default, the disk from which you boot has protected
subsystems enabled but other disks do not. For further details on
subsystems, see the VSI OpenVMS Guide to System Security.
2.19 /UNLOAD
/UNLOAD (default)
/NOUNLOAD
Specifies whether the volume is unloaded (spun down) when the DCL
command DISMOUNT is entered.
2.20 /USER_NAME
/USER_NAME[=user-name]
Specifies a user name of up to 12 alphanumeric characters to be
recorded on the volume. The default name is the current process
user name.
2.21 /VOLUME_CHARACTERISTICS
/VOLUME_CHARACTERISTICS=([[NO]HARDLINKS,] [[NO]ACCESS_
DATES[=delta-time]])
Enables or disables hardlinks and automatic updates of access
dates on ODS-5 volumes.
To limit the performance impact if a file is accessed frequently,
you can suppress update of the access time if the change is
small. A delta time is used to determine when a new access time
is significant. The default value for delta-time is 1 second,
chosen to comply with the "seconds since EPOCH" time interface
required by POSIX st_atime. A site can choose a larger delta time
to reduce overhead if 1-second granularity is not required.
To disable access date support on a volume, use the SET
VOLUME/VOLUME_CHARACTERISTICS=NOACCESS_DATES command. This
command affects only the node on which the command is issued.
Other nodes are not affected by the change until the next time
the volume is mounted.
2.22 /WINDOWS
/WINDOWS[=n]
Specifies the number of mapping pointers to be allocated for file
windows.
The value of n can be from 7 to 80; the default value is 7.
2.23 /WRITETHROUGH
/WRITETHROUGH
/NOWRITETHROUGH
This qualifier only affects applications such as PATHWORKS that
can request deferred writes to file headers. You use it to
control whether these applications can use the deferred write
feature.
Use /NOWRITETHROUGH to allow these applications to use the
deferred write feature. When one of these applications explicitly
requests a deferred write when updating a file header, control
returns to the application when the I/O request has been queued;
the application does not have to wait until the data is on disk.
Note that although the SHOW DEVICES/FULL command shows the volume
status as write-back caching enabled, the extended file cache
(XFC) will still be in write-through mode.
Use /WRITETHROUGH to disable the deferred write feature, so that
no applications can use it. The SHOW DEVICES/FULL command shows
the volume status as write-through caching enabled.
The deferred write feature is not available on Files-11 ODS-1
volumes.
3 – Examples
1.$ SET VOLUME/DATA_CHECK=(READ,WRITE) DKA5
The SET VOLUME command in this example requests that data
checks be performed following all read and write operations
to DKA5.
2.$ SET VOLUME/FILE_PROTECTION=(S:RWED,O:RWED,G:RE,W:RE) DKA5
The SET VOLUME command in this example sets the default
protection to be applied to all files created on volume DKA5.
System (S) and owner (O) are granted all types of access;
group (G) and world (W) are permitted only to read and execute
files on DKA5.
3.$ SET VOLUME/LABEL=LICENSES DKA5
The SET VOLUME command in this example encodes the label
LICENSES on the volume DKA5. Note that if characters in labels
are entered in lowercase, they are changed to uppercase by the
/LABEL qualifier.
4.$ SET VOLUME/ACCESSED=25/USER_NAME=MANAGER/LOG DKA0:
The SET VOLUME command in this example specifies that 25
directories are to be maintained in system space for ready
access for the volume DKA0. The command also assigns the
user name MANAGER to the volume and displays the volume
specification after the volume is modified.
5.$ SET VOLUME/REBUILD/LOG NODE$DKA2:
%SET-I-MODIFIED, _NODE$DKA2: modified
The SET VOLUME command in this example causes a rebuild
operation to begin on the volume that is mounted on NODE$DKA2.
The /LOG qualifier directs the SET VOLUME command to display a
notification message.
6.$ DISMOUNT/CLUSTER/NOUNLOAD $252$DUA716:
$ MOUNT $252$DUA716: TST716
$ SET VOLUME/LIMIT $252$DUA716:
$ DISMOUNT/NOUNLOAD $252$DUA716:
$ MOUNT/CLUSTER $252$DUA716: TST716
This example shows how to increase the expansion limit of a
volume mounted in a cluster.
7.$ SET VOLUME SYS$DISK/VOLUME_CHARACTERISTICS=NOHARDLINKS
This command disables hard links on SYS$DISK.
8.$ SET VOLUME $DKA100/CACHE=CLEAR_DATA
This command clears the contents of the volume $DKA100 present
in the XFC cache (if any). The caching mode of the volume
$DKA100 is not altered.
9.$ SET VOLUME $DKA100/CACHE=DATA
This command enables XFC caching for the volume $DKA100. The
contents of the volume $DKA100 already present in the XFC cache
is not affected in anyway.
10$ SET VOLUME $DKA100/CACHE=(DATA,CLEAR_DATA)
This command enables XFC caching for the volume $DKA100 and
clears the contents of the volume $DKA100 present in the XFC
cache (if any).