HP-UX Reference (11i v2 07/12) - 1M System Administration Commands N-Z (vol 4)

v
vgchange(1M) vgchange(1M)
If any internationalization variable contains an invalid setting, all internationalization variables default to
"C" (see environ(5)).
EXAMPLES
Activate volume group /dev/vg03:
vgchange -a y /dev/vg03
Deactivate volume group /dev/vg03:
vgchange -a n /dev/vg03
Activate volume group /dev/vg03 without synchronizing extents that are not current on logical volumes
that have Mirror Write Cache turned on:
vgchange -a y -s /dev/vg03
Exclusive Activation
Set up volume group /dev/vg03 for use in a high availability cluster:
vgchange -a n /dev/vg03 # Deactivate volume group
vgchange -c y /dev/vg03 # Enable volume group for HA cluster
vgchange -c y -S y /dev/vg03 # Enable volume group for HA cluster
and mark as sharable
vgchange -a e /dev/vg03 # Activate volume group in exclusive mode
vgchange -a s /dev/vg03 # Activate volume group in shared mode
Activate all volume groups; activate those that are marked for membership in a high availability cluster in
shared mode:
vgchange -a y
Activate all volumes that are marked for membership in a high availability cluster in exclusive mode:
vgchange -a e
Cross Activation
Set up volume group /dev/sh_vg for use in a high availability cluster.
To make configuration changes, to a volume group activated in shared mode, deactivate the volume group
by executing the following command on each cluster node except one:
vgchange -a n sh_vg
On the single node, where the volume group is active:
vgchange -a e -x sh_vg # Change mode to exclusive
vgchange -a s -x sh_vg # After configuration change, change
mode back to shared
WARNINGS
Ordinary Operation
In ordinary operation (that is, without the optional high availability software), it is possible to activate a
volume group for read-write access from more than one physically connected system, leading to a high
potential for data corruption. Therefore, if access is desired from more than one system to a single volume
group, it is important that only one system activate the volume group for read-write access; the other sys-
tems can use read-only access. There is no problem if all systems activate the volume group for read-only
access.
Furthermore, volume group information is only read from the disks during volume group activation.
Dynamic changes to the volume group such as the following are not propagated to other systems sharing
the volume group:
Logical volume configuration changes.
Changes to the status of the mirrored extents.
Bad-block relocation that occurs during write operations.
Because of these limitations, when sharing volume groups between systems, it is recommended that logical
volumes be accessed only by one system at a time. If logical volumes must be accessed simultaneously, the
610 Hewlett-Packard Company − 4 − HP-UX 11i Version 2: December 2007 Update