HP-UX Reference (11i v1 00/12) - 1M System Administration Commands N-Z (vol 4)
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STANDARD Printed by: Nora Chuang [nchuang] STANDARD
/build/1111/BRICK/man1m/naaagt.1m
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v
vgchange(1M) vgchange(1M)
NAME
vgchange - set LVM volume group availability
SYNOPSIS
Activate volume group
/usr/sbin/vgchange -a availability [-l][-p][-q quorum][-s][-P resync_daemon_count]
[vg_name ...]
Assign to high availability cluster and mark volume group sharable
/usr/sbin/vgchange -c cluster -S sharable vg_name
Remarks
MC/ServiceGuard cluster operations require the installation of the optional MC/ServiceGuard software,
which is not included in the standard HP-UX operating system.
Lock Manager cluster operations require the installation MC/LockManager software which is not included
with the standard HP-UX operating system.
Mirrored disk operations require the installation of the optional HP MirrorDisk/UX software, which is not
included in the standard HP-UX operating system.
DESCRIPTION
The vgchange command with the -a option activates or deactivates one or more volume groups.
The vgchange command with the -c option controls the membership of one or more volume groups in a
high availability cluster. The vgchange command with the -c and -S options control the membership of
a volume group and mark it sharable.
The vgchange command without the -P resync_daemon_count option (default) will spawn one
nomwcsyncd process for each
NOMWC/NONE volume group being activated. This may create a lot of
nomwcsyncd processes running concurrently when it activates a large number of NOMWC/NONE volume
groups and overload.
The -P resync_daemon_count option provides a way to control the number of concurrent nomwcsyncd
processes. The count is an advisory number and a different count might be chosen internally if load balance
or other reason is needed. When specified, there are up to resync_daemon_count
+1nomwcsyncd
processes; one of them is the controlling processing to spawn others.
-P 0 will use the system default
(currently defined to be 4).
vg_name must be defined as a volume group in the file /etc/lvmtab .Ifvg_name is omitted, all volume
groups defined in
/etc/lvmtab are affected.
High Availability Cluster Overview
Volume groups can be defined on disk volumes that are connected to two or more systems in a high availa-
bility cluster. This situation has a high potential for data corruption unless special software is used to coor-
dinate shared access to the same volume group by all systems. This coordination is provided by
MC/ServiceGuard or MC/LockManager.
A volume group can be marked as part of a MC/ServiceGuard 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.
A volume group can be marked as a part of an MC/LockManager cluster. In this case, the volume group
can be marked as sharable, and may be activated in shared mode for read-write access by all the nodes in
the cluster. Shared read-write access by multiple cluster nodes is coordinated by MC/LockManager’s distri-
buted lock manager (DLM).
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
logical 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.
HP-UX Release 11i: December 2000 − 1 − Section 1M−−1009
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