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AIX Version 4.3 Commands Reference, Volume 1

chvg Command

Purpose

Sets the characteristics of a volume group.

Syntax

chvg [ -a AutoOn { n | y } ] [ -c ] [ -Q { n | y } ] [-u ] [ -x { n | y } ] [ -t [factor ] ] VolumeGroup

Description

The chvg command specifies whether or not the volume group is automatically activated during the system startup. If there is a volume group that is infrequently used, you may not want it activated at system startup because it uses kernel resources (memory).

Note: To use this command, you must either have root user authority or be a member of the system group.

You can use the Web-based System Manager Volumes application (wsm lvm fast path) run this command. You could also use the System Management Interface Tool (SMIT) smit chvg fast path to run this command.

Flags

-a AutoOn Determines if the volume group is automatically activated during system startup. The AutoOn variable can be either of the following:
n The volume group is not automatically activated during system startup.
y The volume group is automatically activated during system startup.
-c Changes the volume group into a Concurrent Capable volume group. However, the volume group must be varied on in non-concurrent mode for this command to take effect. This flag only applies to AIX Version 4.2 or later.
Note: You can transform a non-concurrent volume group into a Concurrent Capable volume group. However, you can not transform a Concurrent Capable volume group into a non-concurrent capable volume group.
-Q Determines if the volume group is automatically varied off after losing its quorum of physical volumes. The default value is yes. The change becomes effective the next time the volume group is activated.
n
The volume group stays active until it loses all of its physical volumes.
y
The volume group is automatically varied off after losing its quorum of physical volumes.
Note: Run the bosboot or savebase command after the chvg -Q n or chvg -Q y command to update the boot image.
-t [factor] Changes the limit of the number of physical partitions per physical volume, specified by factor. factor should be between 1 and 16.

If factor is not supplied, it is set to the lowest value such that the number of physical partitions of the largest disk in volume group is less than factor x 1016.

If factor is specified, the maximum number of physical partitions per physical volume for this volume group changes to factor x 1016.

Notes:
  1. If the volume group is created in AIX 3.2/4.1.2 in violation of 1016 physical partitions per physical volume limit, this flag can be used to convert the volume group to a supported state. This will ensure proper stale/fresh marking of partitions.
  2. factor cannot be changed if there are any stale physical partitions or there are any open logical volumes in the volume group.
  3. Once volume group is converted, it cannot be imported into AIX 4.3.0 or lower versions.
  4. This flag cannot be used if the volume group is varied on in concurrent mode.
-u Unlocks the volume group. This option is provided if the volume group is left in a locked state by abnormal termination of another LVM operation (such as the command core dumping, or the system crashing).
Note: Before using the -u flag, make sure that the volume group is not being used by another LVM command.
-x Changes the mode which the Concurrent Capable volume group is varied on. The volume group must be varied on in non-concurrent mode for this command to take effect. This flag only applies to AIX Version 4.2 or later.
y
autovaryon the volume group in concurrent mode.
n
autovaryon the volume group in non-concurrent mode.
Note: If the volume group is not created Concurrent Capable, this command has no effect on the volume group.

In order for this auto-varyon into concurrency of the volume group to take effect, you must enter the following line into the /etc/inittab file:

rc_clvmv:2:wait:/usr/sbin/clvm_cfg 2>&1
Attention: This entry must be added after the entry used to initiate srcmstr.

Examples

  1. To cause volume group vg03 to be automatically activated during system startup, enter: 
    chvg -a y vg03
  2. To change the volume group vg03 to a supported state if it is in violation of 1016 physical partitions per physical volume limit, enter 
    chvg -t  vg03
  3. To change the maximum number of physical partitions per physical volume to 2032 and maximum number of physical volumes in volume group vg03 to 16, enter 
    chvg -t 2 vg03

Files

/usr/sbin Directory where the chvg command resides.

Related Information

Commands: bosboot, lsvg, mkvg, savebase, varyonvg.

The Logical Volume Storage Overview in AIX Version 4.3 System Management Guide: Operating System and Devices explains the Logical Volume Manager, physical volumes, logical volumes, volume groups, organization, ensuring data integrity, and allocation characteristics.

Setting up and running Web-based System Management in AIX Version 4.3 System Management Guide: Operating System and Devices.

The System Management Interface Tool (SMIT): Overview in AIX Version 4.3 System Management Guide: Operating System and Devices explains the structure, main menus, and tasks that are done with SMIT.

AIX HACMP/6000 Concepts and Facilities.

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