1 – CHANNEL
Sets CHANNEL management parameters, currently limited to priority
values.
NOTE
If a LAN device/IP interface is disabled for use by
cluster communications, all channels associated with that
device/interface are deleted. This means that all management
settings for that device and its associated channels will be
deleted.
Format
SET CHANNEL nodename
1.1 – Parameter
nodename[,...]
Includes channels to specific nodes, which you can use wildcards
to specify. Each node name can be accompanied by optional
qualifiers to specify local and remote device names. If no local
or remote device name is specified, all channels to the specified
node name are included.
Use the SHOW CHANNEL command to display node names and local and
remote device names.
1.2 – Qualifiers
1.2.1 /EXCLUDE
/EXCLUDE=(nodename[,...])
Excludes channels to specific nodes, which you can use wildcards
to specify. Each node name can be accompanied by optional
qualifiers to specify local and remote device names. If no local
or remote device name is specified, all channels associated with
the specified node are included.
1.2.2 /LOCAL_DEVICE
/LOCAL_DEVICE=(landevicename/IPinterfacename[,...])
Specifies a LAN device/IP interface that identifies the local end
of the channel; you can use wildcards to specify LAN devices/IP
interfaces.
Use the SHOW CHANNEL command to display node names and local and
remote device names, or use the SHOW LAN_DEVICE/SHOW IP_INTERFACE
command to display device names.
1.2.3 /PRIORITY
/PRIORITY=n
Sets the management priority value for channels to selected
nodes. n can be a value between -128 and +127. Suggested values
are:
2 to cause channels to be preferred
-2 to exclude channels
NOTE
Starting with OpenVMS Version 7.3-2, a channel whose
priority is -128 is not used for cluster communications.
The priority of a LAN channel is the sum of the management
priority assigned to the local LAN device and the channel
itself. Similarly the priority of IP channel is the sum of
the management priority assigned to local IP interface and
channel itself. Therefore, you can assign any combination
of channel and LAN/IP device management priority values to
achieve a total of -128.
CAUTION
If you set the priority of all channels to -128, you totally
disable use of the LAN/IP for cluster communication. This
can cause the system to CLUEXIT.
1.2.4 /REMOTE_DEVICE
/REMOTE_DEVICE=(landevicename/IPinterfacename[,...])
Specifies a LAN device/IP interface that identifies the remote
end of the channel; you can use wildcards to specify LAN/IP
devices.
Use the SHOW CHANNEL command to display node names and local and
remote device names, or use the SHOW LAN_DEVICE/SHOW IP_INTERFACE
command to display device names.
Use the SHOW LAN_DEVICE/SHOW IP_INTERFACE command on the remote
node to display remote device names.
1.3 – Example
SCACP> SET CHANNEL/PRIORITY=3 NODE5
The command in this example sets the priorities of all channels
to node NODE5 to 3.
2 – CIRCUIT
Sets the circuit management priority value.
NOTE
If a circuit is closed, it is deleted. This means that the
management settings for that circuit are also deleted. If
the circuit is opened again, it has the default values for
its management settings.
Format
SET CIRCUIT nodename
2.1 – Parameter
nodename[,...]
Names a circuit or circuits to specific nodes, which you can
use wildcards to specify. You can qualify each node name with
additional parameters to uniquely identify a single circuit.
2.2 – Qualifiers
2.2.1 /EXCLUDE
/EXCLUDE=(nodename[/PORT=portname[/RSTATION=n]][,...])
Allows you to exclude a specific circuit to a node. If multiple
circuits to the same node exist, you can use the /PORT and
/RSTATION qualifiers to uniquely identify the circuit.
2.2.2 /PORT
/PORT=portname[/RSTATION=n]
If multiple circuits to the same node exist, you can use the
/PORT and /RSTATION qualifiers to uniquely identify the circuit.
You can use the /RSTATION qualifier only in conjunction with the
/PORT qualifier.
2.3 – Example
SCACP> SET CIRCUIT CLUIO1 /PORT=PIB0 /PRI=10
The command in this example sets the priority of the circuit
to node CLUIO1 through PIB0 to 10. You need to use the /PORT
qualifier if multiple circuits to node CLUI01 exist and only
the circuit through PIB0 is meant to have its priority raised.
3 – IP_INTERFACE
Sets IP interface management priority parameter.
Format
SET IP_INTERFACE ipinterface
3.1 – Parameter
ipinterface[,...]
Includes one or more specific IP interface, which you can use
wildcards to specify.
o Use the /EXCLUDE qualifier to exclude an IP interface.
o Use the SHOW IP_INTERFACE command to display device names.
3.2 – Qualifiers
3.2.1 /EXCLUDE
/EXCLUDE=(ipinterface1[,...])
Excludes one or more specific IP interface which you can use
wildcards to specify.
3.2.2 /PRIORITY
/PRIORITY=n
Sets the management priority value for the selected interfaces. n
can be a value between -128 and +127. Suggested values are:
o 2 to cause devices to be preferred
o -2 to exclude devices
NOTE
Starting with OpenVMS Version 7.3-2, a channel whose
priority is -128 is not used for cluster communications.
The priority of a channel is the sum of the management
priority assigned to the IP interface and the channel
itself. Therefore, you can assign any combination of channel
and IP interface management priority values to achieve a
total of -128.
CAUTION
If you set the priority of all devices to -128, you totally
disable use of the IP for cluster communication. This can
cause the system to CLUEXIT.
3.2.3 /SOCKET_RECEIVE
/SOCKET_RECEIVE=n
Sets the socket's receive buffer size (in bytes) for the IP BUS. The
default value is 178432 bytes, which is 128 times the maximum buffer
size on an IP Channel. 'n' can be a value between 0 and 137035776. To
reset the socket buffer size for the IP bus, set 'n' to 0. If the
management provided value is lesser than the initial default, it is
ignored.
NOTE
The maximum socket buffer size is limited by tcpip configuration
and by default it is 1MB. It can be obtained by the following
command:
$ tcpip sysconfig -q socket sb_max
To increase the size of IP bus' receive socket buffer beyond
1MB, sb_max parameter has to be increased. Refer to "HP TCP/IP
Services for OpenVMS Tuning and Troubleshooting" for information
on changing sb_max.
3.3 – Example
SCACP> SET IP_INTERFACE/PRIORITY=3 WE0
The command in this example sets the management priority for
device WE0 to 3.
4 – LAN_DEVICE
Sets device management priority parameter.
Format
SET LAN_DEVICE landevicename
4.1 – Parameter
landevicename[...,]
Includes specific LAN devices, which you can use wildcards to
specify.
Use the /EXCLUDE qualifier to exclude LAN devices.
Use the SHOW LAN_DEVICE command to display device names.
4.2 – Qualifiers
4.2.1 /EXCLUDE
/EXCLUDE=(landevicename1[,...])
Excludes one or more specific LAN devices, which you can use
wildcards to specify.
4.2.2 /PRIORITY
/PRIORITY=n
Sets the management priority value for the selected devices. n
can be a value between -128 and +127. Suggested values are:
o 2 to cause devices to be preferred
o -2 to exclude devices
NOTE
Starting with OpenVMS Version 7.3-2, a channel whose
priority is -128 is not used for cluster communications. The
priority of a channel is the sum of the management priority
assigned to the local LAN device and the channel itself.
Therefore, you can assign any combination of channel and
LAN device management priority values to achieve a total of
-128.
CAUTION
If you set the priority of all devices to -128, you totally
disable use of the LAN for cluster communication. This can
cause the system to CLUEXIT.
4.3 – Example
SCACP> SET LAN_DEVICE/PRIORITY=3 EWA
The command in this example sets the management priority for
device EWA to 3.
5 – PORT
Sets a port management priority value.
Format
SET PORT portname
5.1 – Parameter
portname[,...]
Specifies SCA port names, in which you can include wildcards.
Use the /EXCLUDE qualifier to exclude specific ports.
Use the SHOW PORT command to display all ports available on your
system.
5.2 – Qualifiers
5.2.1 /EXCLUDE
/EXCLUDE=(portname[,...])
Excludes specific ports from the operation.
5.2.2 /PRIORITY
/PRIORITY=n
Sets the management priority value for the selected ports. n can
be any value between -128 and +127.
5.3 – Examples
1.SCACP> SET PORT PEA0/PRIORITY=5
The command in this example sets the management priority for
the PEA0 port to 5.
2.SCACP> SET PORT PEA0 /PRIORITY=5 /EXCLUDE=PEA0
The command in this example sets all ports with the exception
of PEA0 to a management priority of 5.
6 – TRACE
SET TRACE sets or modifies PEdriver tracing parameters.
NOTE
This command is reserved for use by VSI Services and OpenVMS
Engineering only. Trace commands and output are subject to
change from release to release.
Format
SET TRACE nodename
6.1 – Parameter
nodename[,...]
Includes channels and VCs to specific nodes, which you can
use wildcards to specify. Each node name can be accompanied by
optional qualifiers to specify local and remote device names.
If no local or remote device name is specified, all channels
associated with the specified node are included, as well as the
VC to the specified node.
Use the SHOW CHANNEL command to display node names and local and
remote device names.
6.2 – Qualifiers
6.2.1 /AFTER
/AFTER=n
After the trace stop condition has been satisfied, continue
tracing for n events, and then stop. If you do not specify
/AFTER, tracing does not continue after the trace stop event.
n can be any value between 0 and FFFFFFF.
6.2.2 /DEFAULT
Sets the trace context back to the default settings, which are:
trace all channels and VCs
/AFTER=0
/EVENT=default settings
/STOP
/SIZE=512
6.2.3 /EVENT
/EVENT=(event1[,...])
Enables tracing on specific events, which you can use wildcards
to specify. The default is a subset of the events, which includes
most errors and state changes when the system parameter SYSTEM_
CHECK is set to 0. The default is "all events included" when
SYSTEM_CHECK is set to 1.
Use the SHOW TRACE/CONTEXT command to display event names.
6.2.4 /EXCLUDE
/EXCLUDE=(nodename[/LOCAL_
DEVICE=landevicename/ipinterfacename]
[/REMOTEDEVICE=landevicename/ipinterfacename][,...])
Excludes VCs or channels, or both, to specific nodes, which you
can use wildcards to specify. Each node name can be accompanied
by optional qualifiers to specify local and remote device names.
If no local or remote device name is specified, the VC and all
channels associated with the specified node are excluded.
6.2.5 /LOCAL_DEVICE
/LOCAL_DEVICE=(landevicename/ipinterfacename[,...])
Includes specific LAN devices that identify the local end of the
channel. You can use wildcards to specify LAN devices.
6.2.6 /REMOTE_DEVICE
/REMOTE_DEVICE=(landevicename/ipinterfacename[,...])
Includes specific LAN devices that identify the remote end of the
channel; you can use wildcards to specify LAN devices.
Use the SHOW LAN_DEVICE command to display device names.
6.2.7 /STOP
/STOP=(event1[,...])
Stops tracing on specific events, which you can use wildcards to
specify. The default is "no events included."
Use the SHOW TRACE/CONTEXT command to display event names.
6.2.8 /SIZE
/SIZE=n
Specifies a trace buffer size of n bytes to be used by PEdriver
for each trace buffer: one for global PEdriver use, one for each
selected channel, and one for each selected VC. n can be any
value between 0 and FFFFFFF.
6.3 – Examples
1.SCACP> SET TRACE/EVENT=CC_STATE/SIZE=1000
The command in this example specifies that the trace buffers
for each channel, VC, and the global buffer each be 1000 bytes
in length.
2.SCACP> SET TRACE/EVENT=* NODE10/LOCAL=EWA,NODE20
The command in this example specifies that all events are to be
recorded; when applicable to a particular node, however, only
channels and VCs to nodes NODE10 and NODE20 are to be included.
3.SCACP> SET TRACE/EVENT=(ALL,NOTIMER) NODE10
The command in this example specifies that all events except
timer events on node NODE10 are to be included.
7 – VC
Sets values for the virtual circuit management parameters
(checksumming, compression, ECS delay threshold, transmit window
size, and receive window size values).
Format
SET VC nodename
7.1 – Parameter
nodename[,...]
Includes VCs to specific nodes, which you can use wildcards to
specify.
Use the /EXCLUDE qualifier to exclude VCs to specific nodes.
Use the SHOW CHANNEL or SHOW VC command to display VC names,
which are simply the names of remote nodes.
7.2 – Qualifiers
7.2.1 /CHECKSUMMING
/CHECKSUMMING
/NOCHECKSUMMING
Enables or disables checksum verification on the selected VCs to
the specified nodes.
You can use this command alone or in combination with the system
parameter NISCS_PORT_SERV. (For more information, see online help
for NISCS_PORT_SERV.)
Note that the the SET VC/CHECKSUMMING setting is not valid beyond
the life of the system. Therefore, you might want to include SET
VC/CHECKSUMMING commands in your startup file, or reissue these
commands at the next boot.
7.2.2 /COMPRESSION
/COMPRESSION
/NOCOMPRESSION
Enables or disables sending compressed data by the specified VCs.
The default is /NOCOMPRESSION.
Usage notes:
o Compression is used only if the partner node has a PEdriver
version that supports it.
o You can also enable the use of compression with the NISCS_
PORT_SERV system parameter. For more information about NISCS_
PORT_SERV, see the System Parameter appendix in this manual.
o The /NOCOMPRESSION qualifier does not override compression
enabled by setting bit 2 of NISCS_PORT_SERV.
7.2.3 /ECS_MAX_DELAY
/ECS_MAX_DELAY=n
/NOECS_MAX_DELAY
Sets a management-specified lower bound on the maximum delay (in
microseconds) an ECS member channel can have. The value for n can
be any value between 0 and 3000000. /NOECS_MAX_DELAY disables a
prior management delay setting.
You can use this command to override the PEdriver automatically
calculated delay thresholds to ensure that all channels with
delays less than the value supplied for n are included in the
VC's ECS.
The command operates as follows: Whenever at least one tight peer
channel has a delay of less than the management-supplied value,
all tight peer channels with delays less than the management-
supplied value are automatically included in the ECS. When all
tight peer channels have delays equal to or greater than the
management setting, the ECS membership delay thresholds are
automatically calculated and used. The /NOECS_MAX_DELAY qualifier
disables management control by setting the management delay value
to zero.
You must determine an appropriate value for your configuration by
experimentation. An initial value of 2000 (2 ms) to 5000 (5 ms)
is suggested.
CAUTION
By overriding the automatic delay calculations, you
can include a channel in the ECS whose average delay is
consistently greater than 1.5 to 2 times the average delay
of the fastest channels. When this occurs, the overall
VC throughput becomes the speed of the slowest ECS member
channel.
An extreme example is when the management delay permits a
10 Mb/s Ethernet channel to be included with multiple 1 Gb/s
channels. The resultant VC throughput drops to 10 Mb/s.
Note that the SET VC/ECS_MAX_DELAY setting is not valid beyond
the life of the system. Therefore, you might want to include SET
VC/ECS_MAX_DELAY commands in your startup file or reissue these
commands at the next boot.
7.2.4 /EXCLUDE
/EXCLUDE=(nodename[,...])
Excludes VCs to specific nodes, which you can use wildcards to
specify.
7.2.5 /WINDOW
/WINDOW=RECEIVE=n
/WINDOW=NORECEIVE
Sets a management-specified upper bound on the receive window
size (that is, the number of out-of-order packets this VC holds
in its resequencing cache while awaiting the next in-order packet
or packets).
You can use this qualifier to override the automatically
calculated receive window size. This ensures that the VC has
enough buffering to receive the expected maximum number of out-
of-order packets.
Usage notes:
o The window size value n must be an exact power of 2.
Never use settings that cause the receive window of a VC to
be smaller than the transmit window of the partner node.
Otherwise, the partner can send packets that cannot be
cached when a packet is lost. This results in unnecessary
retransmissions, and might cause channels not to be used
because they become "lossy." This leads to the remaining
restrictions listed.
o Always decrease the receive window size of a VC's partner node
before decreasing a VC's receive window size.
VSI recommends using SYSMAN to decrease both the local and the
remote VC transmit window sizes before increasing the local
and remote receive window sizes (as shown in the example).
o Always increase the receive window size of a VC's partner node
before increasing a VC's transmit window size.
VSI recommends using SYSMAN to increase both the local and the
remote VC receive window sizes before increasing the local and
remote transmit window sizes.
o Whenever you enter the SET VC/WINDOW=RECEIVE command, the
following sequence of events occurs:
1. The VC's current resequencing cache is emptied.
2. The VC partner node automatically retransmits any discarded
packets.
3. As a result of 2, the VC and channel retransmit counts
increase.
4. A few messages similar to the following might be displayed,
indicating that one or more channels has temporarily become
"lossy":
%PEA0, Excessive packet losses on LAN Path from EWA to EWC
on REMOTE NODE STAR
5. The partner node recovers automatically within a few
seconds.
o You can use the SCACP> CALCULATE WINDOW_SIZE command to assist
you in selecting the size to use for transmit and receive
windows.
7.2.6 /WINDOW
/WINDOW=TRANSMIT=n
/WINDOW=NOTRANSMIT
Sets a management-specified upper bound on the transmit window
size (that is, the number of out-of-order packets this VC sends
while awaiting acknowledgment of the transmitted packets) to n.
The /WINDOW=NOTRANSMIT qualifier resumes automatic control of the
window size and changes the management transmit window size to
zero.
You can use the /WINDOW=TRANSMIT qualifier to override the
automatically calculated transmit window size to ensure that the
VC has enough buffering to receive the expected maximum number of
out-of-order packets.
Usage notes:
o The window size value n must be an exact power of 2.
Never use settings that cause the receive window of a VC to
be smaller than the transmit window of the partner node.
Otherwise, the partner can send packets that cannot be
cached when a packet is lost. This results in unnecessary
retransmissions, and might cause channels not to be used
because they become "lossy". This leads to the following
restrictions.
o Always decrease the transmit window size of a VC's partner
node before decreasing a VC's receive window size.
VSI recommends using SYSMAN to decrease both the local and the
remote VC transmit window sizes before increasing the local
and remote receive window sizes.
o Always increase the receive window size of a VC's partner node
before increasing a VC's transmit window size.
VSI recommends using SYSMAN to increase both the local and the
remote VC receive window sizes before increasing the local and
remote transmit window sizes (as shown in the example).
o You can use the SCACP CALCULATE WINDOW_SIZE command to assist
you in selecting the size to be used for transmit and receive
windows.
7.3 – Examples
1. $RUN SYS$SYSTEM:SYSMAN
SYSMAN> SET ENV/NODE=LARRY
DO MC SCACP SET VC LARRY/WINDOW=TRANSMIT=16
SET ENV/NODE=CURLY
DO MC SCACP SET VC CURLY/WINDOW=TRANSMIT=16
SET ENV/NODE=LARRY
DO MC SCACP SET VC LARRY/WINDOW=RECEIVE=16
SET ENV/NODE=CURLY
DO MC SCACP SET VC CURLY/WINDOW=RECEIVE=16
EXIT
This example shows how to decrease window size. The transmit
and receive window sizes are 32 on both nodes, and the commands
decrease the window size for the VC between LARRY and CURLY.
(You can enter the commands on either node.)
2. $RUN SYS$SYSTEM:SYSMAN
SYSMAN> SET ENV/NODE=LARRY
DO MC SCACP SET VC LARRY/WINDOW=RECEIVE=64
SET ENV/NODE=CURLY
DO MC SCACP SET VC CURLY/WINDOW=RECEIVE=64
SET ENV/NODE=LARRY
DO MC SCACP SET VC LARRY/WINDOW=TRANSMIT=64
SET ENV/NODE=CURLY
DO MC SCACP SET VC CURLY/WINDOW=TRANSMIT=64
EXIT
This example shows how to increase window size. The transmit
and receive window sizes are 32 on both nodes, and the commands
increase the window size for the VC between LARRY and CURLY.
(You can enter the commands on either node.)