/ABORT_VIRTUAL_UNIT DSAnnnn: (Alpha/Integrity servers only)
Aborts mount verification on a shadow set.
Use this qualifier when you know that the unit cannot be recovered.
When you use this qualifier, the shadow set must be in mount
verification. The shadow set aborts mount verification immediately on
the node from which the command is issued. If the shadow set is not in
mount verification, this command returns the error
%SYSTEM-E-UNSUPPORTED, unsupported operation or function.
After this command completes, the shadow set still must be dismounted.
Use the following command to dismount the shadow set:
$ DISMOUNT/ABORT DSAnnnn:
|
/AVAILABLE
/NOAVAILABLE
Controls whether the specified disk or magnetic tape is to be
considered available. You must dismount the specified disk or magnetic
tape before entering the SET DEVICE/[NO]AVAILABLE command. If you
specify the /NOAVAILABLE qualifier, any attempt to allocate or mount
the specified disk or magnetic tape is prevented. Devices are
automatically set /AVAILABLE when brought online even if the device had
been previously set /NOAVAILABLE.
/COPY_SOURCE {ddcu: | DSAnnnn:} (Alpha/Integrity servers only)
Specifies which source member of a shadow set will be used as the
source for read data during full copy operations when a third member is
added to the shadow set. This qualifier affects only copy operations
that do not use disk copy data (DCD) commands.
Some storage controllers, such as the HSG80, have a read-ahead cache,
which significantly improves single-disk read performance. Copy
operations normally alternate reads between the two source members,
which effectively nullifies the benefits of the read-ahead cache. This
qualifier lets you force all reads from a single, specified source
member for a copy operation.
If only a shadow set (DSAnnnn:) is specified, all reads for
full copy operations will be performed from the disk that is the
current "master" member, regardless of physical location of
the disk.
If a shadow set member (ddcu:) is specified, that member will
be used as the source of all copy operations. This allows you to choose
a local source member, rather than a remote master member.
/DUAL_PORT
/NODUAL_PORT
Controls whether the port seize logic in the device driver of the
specified disk is to be enabled. This qualifier should be used only on
disks that contain a dual port kit and have been dismounted.
/ENABLE
/NOENABLE
Enables or disables a path to a multipath device; the affected path is
the one named in the /PATH qualifier. All paths are initially enabled;
the current path cannot be disabled.
/ERROR_LOGGING
/NOERROR_LOGGING
Controls whether device errors are logged in the error log file. When
you specify the /ERROR_LOGGING qualifier, all error messages reported
by the device on which error logging is enabled are recorded in the
error log file. Use the SHOW DEVICE/FULL command to find out the
current status.
/FORCE_REMOVAL ddcu: (Alpha/Integrity servers only)
Expels the specified shadow set member from the shadow set.
If connectivity to a device has been lost and the shadow set is in
mount verification, this qualifier causes the member to be expelled
from the shadow set immediately.
If the shadow set is not currently in mount verification, no immediate
action is taken. If connectivity to a device has been lost but the
shadow set is not in mount verification, this qualifier lets you flag
the member to be expelled from the shadow set, as soon as it does enter
mount verification.
The specified device must be a member of a shadow set that is mounted
on the node where the command is issued.
/LOG
/NOLOG (default)
Controls whether log information is displayed at the terminal.
/MEMBER_TIMEOUT=n ddcu: (Alpha/Integrity servers only)
Specifies the timeout value to be used for a shadow set member.
The value supplied by this qualifier overrides the system parameter
SHADOW_MBR_TMO for this specific device. Each member of a shadow set
can be assigned a different MEMBER_TIMEOUT value.
The valid range for n is 1 to 16777215 seconds.
The specified device must be a member of a shadow set that is mounted
on the node where the command is issued.
/MV_INTVL=n
Overrides the systemwide setting of the MVSUPMSG_INTVL system parameter
with the value specified by n (seconds) for the specified
device only. If /MV_INTVL=0, the value for MVSUPMSG_INTVL is used
instead. If MVSUPMSG_INTVL=0 or MVSUPMSG_NUM=0, all mount verifications
are announced. For more information about MVSUPMSG_INTVL, see the
HP OpenVMS System Management Utilities Reference Manual.
/MV_NUM=n
Overrides the systemwide setting of the MVSUPMSG_NUM system parameter
with the value specified by n (seconds) for the specified
device only. If /MV_NUM=0, the value for MVSUPMSG_NUM is used instead.
If MVSUPMSG_NUM=0 or MVSUPMSG_INTVL=0, all mount verifications are
announced. For more information about MVSUPMSG_NUM, see the
HP OpenVMS System Management Utilities Reference Manual.
/MVTIMEOUT=n DSAnnnn: (Alpha/Integrity servers only)
Specifies the mount verification timeout value to be used for the
shadow set specified by its virtual unit name (DSAnnnn:).
The value supplied by this qualifier overrides the value specified by
the system parameter MVTIMEOUT for this specific shadow set.
Note
You cannot change the value of MVTIMEOUT for a system disk. Any attempt
to do so results in an error.
|
The valid range for n is 1 to 16777215 seconds.
The specified shadow set must be mounted on the node where the command
is issued.
/PATH=path-description-string
(For multipath devices only) Specifies a particular route to the
device. The path description string identifies a path from the host to
the device (for example, PGA0.2343-A855-BC99-876F or PKC0.5). Wildcard
characters have no special meaning. The path description can be
abbreviated to the minimum unique string.
Note that this qualifier does not imply that any action be taken. To
take action, you must also specify one of the following qualifiers:
/(NO)ENABLE, /(NO)POLL, or /SWITCH.
/POLL
/NOPOLL
Specifies that the path specified by the /PATH qualifier is to be
polled for continued availability as a path switch destination. This
does not affect any attempt to switch to this path. Its purpose is only
to inform an operator that a path may or may not be viable as a path
switch destination. By default, all device paths are enabled for
polling when they are discovered. Note that this qualifier applies only
to multipath devices.
/PREFERRED_CPUS=cpu-a[,cpu-b,cpu-c,...]
/NOPREFERRED_CPUS
Allows you to specify a CPU or a set of candidate CPUs from which the
operating system chooses the CPU to assign to the Fast Path port. The
chosen CPU is called the preferred CPU for this Fast Path port. The
Fast Path port's interrupt I/O completion processing and I/O initiation
processing are performed on this preferred CPU.
In addition to selecting the preferred CPU, the User Preferred CPU is
set for this port. Setting the User Preferred CPU prevents the port
from being reassigned to another CPU unless the User preferred CPU is
being stopped. The qualifier can be negated. When the /NOPREFERRED_CPUS
qualifier is specified, the User Preferred CPU is cleared for the port,
but it remains a Fast Path port, and the current preferred CPU is not
changed.
If both /PREFERRED_CPUS and /NOPREFERRED_CPUS are specified on the same
command line, /NOPREFERRED_CPUS is ignored.
If Fast Path is enabled, you can use the DCL command, SHOW DEVICE/FULL,
to display the current preferred CPU and the User Preferred CPU.
For more information about using Fast Path features to improve I/O
performance, see the HP OpenVMS I/O User's Reference Manual.
/READ_COST=n {ddcu: | DSAnnnn:} (Alpha/Integrity servers only)
Enables you to modify the default cost assigned to each shadow set
member (ddcu:). By modifying the assignments, you can bias the
reads in favor of one member of a two-member shadow set, or, in the
case of three-member shadow sets, in favor of one or two members of the
set over the remaining members. The device specified must be a shadow
set or member of a shadow set that is mounted on the node where the
command is issued.
The valid range for the specified cost is 1 to 65,535 units.
The shadowing driver assigns default READ_COST values to shadow set
members when each member is initially mounted. The default value
depends on the device type and its configuration relative to the system
mounting it. The following list of device types is ordered by the
default READ_COST assignments, from the lowest cost to the highest cost:
- DECram device
- Directly connected device in the same physical location
- Directly connected device in a remote location
- DECram served device
- Default value for other served devices
The value supplied by the /READ_COST qualifier overrides the default
assignment. The shadowing driver adds the value of the current queue
depth of the shadow set member to the READ_COST value and then reads
from the member with the lowest value.
Different systems in the cluster can assign different costs to each
shadow set member.
When this qualifier specifies a shadow set (DSAnnnn:) instead
of a shadow set member, the /READ_COST qualifier switches the read cost
setting for all shadow set members back to the default read
cost settings established automatically by the shadowing software. The
specified shadow set must be mounted on the node where the command is
issued. In this case, the value specified for the cost can be any
number because it will be ignored.
If the /SITE command qualifier has been specified, the shadowing driver
takes site values into account when it assigns default READ_COST
values. In order for the shadowing software to determine whether a
device is in the category of "directly connected device in a
remote location," the /SITE command qualifier must have been
applied to both the shadow set and the shadow set member.
Reads requested for a shadow set from a system at site 1 are performed
from a shadow set member that is also at site 1. Reads requested for
the same shadow set from site 2 can read from the member located at
site 2.
/RESET=(keyword[,keyword])
Requires CMKRNL and DIAGNOSE privileges.
Resets either or both the error count and the operation count for a
device. You must specify one or both of the following keywords:
|
ERROR_COUNT
|
Resets the error count.
|
|
OPERATION_COUNT
|
Resets the operation count.
|
When either count is reset, a message is sent to the error log. The
message indicates that the count was reset and includes the value of
the counter before the reset.
/SITE=n {DSAnnnn: | ddcu:} (Alpha/Integrity servers only)
Indicates to the shadowing driver the site location of the specified
shadow set (DSAnnnn:) or shadow set member (ddcu:).
If the member is removed from the shadow set and later is returned,
this qualifier must be specified again.
The SHADOW_SITE_ID system parameter defines the default site location
of the shadow set. You can override the default location of the shadow
set with the /SITE qualifier.
The valid range for the site location, represented by n, is 1
through 255.
After you apply this qualifier, the setting remains in effect until you
change it either with this command or with the SET SHADOW/SITE command.
This qualifier can improve read performance because the member that is
physically local to the system will be the preferred disk from which to
read, provided that you specify the /SITE qualifier for each shadow set
member and for the shadow set. (In a Fibre Channel configuration,
shadow set members at different sites are directly attached to the
system. For the Volume Shadowing and cluster software, there is no
distinction between local and remote in multiple-site Fibre Channel
configurations.)
/SPOOLED[=(queue-name[:],intermediate-disk-name[:])]
/NOSPOOLED
Controls whether files are spooled to an intermediate disk.
The queue name indicates the printer queue to which a file is queued.
If a queue name is not supplied, the default is the name of either the
printer or terminal.
The intermediate disk name identifies the disk to which the spooled
files are written. If the intermediate disk name is not supplied, the
default is SYS$DISK (the current default disk). The intermediate disk
must be mounted before files can be written to it.
Once the device has been set spooled to a disk, that disk cannot be
dismounted until the spooled device is set to /NOSPOOLED. All channels
must be deassigned from a print device before its spooling
characteristics can be changed. Also, the queue that is assigned to the
device must be stopped.
/SWITCH
Attempts to switch from the current path of a multipath device to the
path named in the /PATH qualifier. The path switch is attempted only if
the path has not been disabled by SET DEVICE/NOENABLE. The path switch
is initiated but not completed before returning control to the user;
use SHOW DEVICE/MULTIPATH to verify that the path switching has
completed successfully.
This command requires the OPER privilege. Additionally, if the device
is currently allocated by another process, as tape devices often are,
the SHARE privilege is needed.
