vgchange.1m (2010 10)

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vgchange(1M) vgchange(1M)

High Availability Cluster Overview

Volume groups can be deﬁned on disk volumes that are accessible by more than one system in a high

availability cluster. This situation has a high potential for data corruption unless higher level cluster

software services are used to coordinate shared access to the same volume group by all systems.

A volume group can be marked as part of a cluster. When such a group is activated in exclusive mode, it

can be accessed for exclusive read-write activity by only one of the systems at a time; the other systems

can have read-only access to the data. When the volume group is also marked as sharable, it may be

activated in shared mode for read-write access by all the nodes in the cluster.

The conﬁguration of a shared volume group can be changed only if it is activated in exclusive mode.

Cross-activation between shared and exclusive modes of shared volume groups is possible with the

-x

option to vgchange.

Simultaneously quiescing a volume group on all the systems sharing the volume group can be accom-

plished by invoking

vgchange with the -Q

option from any node in the cluster. A Serviceguard cluster-

lock volume group cannot be quiesced, because initializing or updating the cluster-lock requires writing to

the disk.

Options and Arguments

vgchange recognizes the following options and arguments:

vg_name The path name of a volume group.

-a availability Set volume group availability. availability can have one of the following values:

y Activate each speciﬁed volume group and all associated physical and logi-

cal volumes for read-write access.

If a volume group is marked as part of a high availability cluster, it is

activated in exclusive read-write mode, as for the

-a e option.

e Activate each speciﬁed volume group and all associated physical and logi-

cal volumes for exclusive read-write access. The volume group must be

marked as part of a high availability cluster, and the availability software

must be running on the system; otherwise, the volume group is not

activated.

With the

-x option, the activation mode of a shared volume group is

changed to exclusive. The volume group will remain active during the

operation. The operation will not be performed if the volume group is

active in more than one node, or if it is not currently in shared mode.

s Activate each speciﬁed volume group and all associated physical and logi-

cal volume for shared read-write access. The volume group must be

marked as part of a high availability cluster and marked sharable; other-

wise, the volume group is not activated.

Please note HP MirrorDisk/UX software is only supported in a clustered

environment with a maximum of two nodes conﬁgured for volume group

version 1.0 and 2.0. For volume group version 2.1 or higher, HP

MirrorDisk/UX software is supported in a clustered environment with a

maximum of sixteen nodes conﬁgured.

With the

-x option, the activation mode of a shared volume group is

changed to shared. The volume group will remain active during the opera-

tion. The operation will only be performed if the current activation mode

of the volume group is exclusive.

If the

-a y or -a e option is executed on a currently active volume group,

without the -x option, vgchange attempts to include any physical volumes

that were previously listed as missing. This is useful if a physical volume has

come back online. However, no automatic synchronization of any mirrored logi-

cal volumes is done. If synchronization is required, execute the vgsync com-

mand (see vgsync (1M)).

r Activate each speciﬁed volume group and all associated physical and logi-

cal volumes for read-only access. This option is ignored for a volume group

that is already activated.

2 Hewlett-Packard Company − 2 − HP-UX 11i Version 3: October 2010