pvchange.1m (2010 09)
p
pvchange(1M) pvchange(1M)
each of the systems in the cluster.
Alternate Links (PVLINKS)
In this release of HP-UX, LVM continues to support Alternate Links to a device to allow continued access
to the device, if the primary link fails. This multiple link or multipath solution increases data availabil-
ity, but does not allow the multiple paths to be used simultaneously.
There is a new feature introduced in the Mass Storage Subsystem on this version of HP-UX that also sup-
ports multiple paths to a device and allows access to the multiple paths simultaneously. The Mass
Storage Subsystem will balance the I/O load across the valid paths. This new multi-path behavior is
enabled and disabled through the use of the
scsimgr command. See scsimgr (1M) for details.
It is no longer required or recommended to configure LVM with alternate links. However, it is possible to
maintain the traditional LVM behavior. To do so, both of the following criteria must be met:
• Only the legacy device special file naming convention is used in the volume group configuration.
• The
scsimgr command is used to disable the Mass Storage Subsystem multipath behavior.
EXTERNAL INFLUENCES
Environment Variables
LANG determines the language in which messages are displayed.
If
LANG is not specified or is null, it defaults to C (see lang(5)).
If any internationalization variable contains an invalid setting, all internationalization variables default
to
C (see environ (5)).
EXAMPLES
Prohibit the allocation of additional physical extents to a physical volume:
pvchange -x n /dev/dsk/c0t0d0
Allow the allocation of additional physical extents to a physical volume:
pvchange -x y /dev/dsk/c0t0d0
Only switch paths when the current path is unavailable. Do not switch back to a prior path which had
failed and has recovered, when the current path works:
pvchange -S n /dev/dsk/c0t0d0
Switch paths whenever a better path becomes available again after a failure, even if the current path is
fine:
pvchange -S y /dev/dsk/c0t0d0
Manually switch a physical volume to use another controller path:
pvchange -s /dev/dsk/c2t0d2
Set the IO_timeout value for a physical volume to 60 seconds:
pvchange -t 60 /dev/dsk/c2t0d2
Set the IO_timeout value for a physical volume to zero (0) to use the driver default:
pvchange -t 0 /dev/dsk/c2t0d2
Change the (empty) physical volume to become a stand-by spare for the volume group:
pvchange -z y /dev/dsk/c2t0d2
Change the (active or stand-by) spare physical volume to become a regular member of the volume group:
pvchange -z n /dev/dsk/c2t0d2
Enable LVM’s proactive polling of alternate links
pvchange -p y /dev/dsk/c2t0d2
Disable LVM’s proactive polling of alternate links
pvchange -p n /dev/dsk/c2t0d2
Detach a path to a physical volume
4 Hewlett-Packard Company − 4 − HP-UX 11i Version 3: September 2010