extendvg Command

Purpose

Adds physical volumes to a volume group.

Syntax

extendvg [ -f ] [-p mirrorpool] volumegroup physicalvolume ...

Description

The extendvg command increases the size of the volumegroup by adding one or more physicalvolumes.

The physical volume is checked to verify that it is not already in another volume group. If the system believes the physical volume belongs to a volume group that is varied on, it exits. But if the system detects a description area from a volume group that is not varied on, it prompts the user for confirmation in continuing with the command. The previous contents of the physical volume are lost, so the user must be cautious when using the override function.

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

For volume groups created prior to AIX® 5.3, or for volume groups created on AIX 5.3 but varied on with the varyonvg -M flag, the extendvg will fail if the physical volume has a max transfer size that is smaller than the logical track group size of the volume group. For volume groups created on AIX 5.3 and varied on without the varyonvg -M flag, extendvg will dynamically lower the logical track group size of the volume group if the physical volume has a max transfer size that is smaller than the logical track group size of the volume group.

Note: The extendvg command is not allowed on a snapshot volume group.

You can use the System Management Interface Tool (SMIT) smit extendvg fast path to run this command.

Note: This command will fail to add a disk to the volume group if the disk indicates that it is managed by a third party volume manager. To override and clear the disk of the third party volume manger use chpv -C HDiskName.

Note: When extending a concurrent Volume Group (VG), you must first ensure that each new disk to be added to the VG has a Physical Volume Identifier (PVID) assigned, and that the PVID stored in the Object Data Manager (ODM) is the same one on every node. When using the Cluster Single Point of Control (C-SPOC) utility to extend the VG, this check is done automatically.

Note: The VG is checked to determine if an existing PV type restriction is in place. If such a restriction exists, the physical volume(s) list on the extendvg command line are examined to ensure that they meet the restriction. If one or more of the disks is found to not meet the PV type restriction, the command will fail.

Note: You cannot mix physical volume (PV) of 4 KB block size with PV blocks of other sizes. The block size of all PVs in the volume group must be the same.

Flags

Item	Description
-f	Forces the physical volume to be added to the specified volume group unless it is a member of another volume group in the Device Configuration Database or of a volume group that is active.
-p mirrorpool	Assigns each of the physical volumes being added to the specified mirror pool. After mirror pools are enabled in a volume group, the volume group can no longer be imported into a version of AIX that does not support mirror pools.

Security

Attention RBAC users and Trusted AIX users: This command can perform privileged operations. Only privileged users can run privileged operations. For more information about authorizations and privileges, see Privileged Command Database in Security. For a list of privileges and the authorizations that are associated with this command, see the lssecattr command or the getcmdattr subcommand.

Examples

To add physical volumes hdisk3 and hdisk8 to volume group vg3, enter:

extendvg vg3 hdisk3 hdisk8

Note: The volume group must be varied on before extending.

Restrictions

The extendvg command cannot be run on a snapshot volume group.

Files

Item	Description
/usr/sbin/extendvg	Contains the extendvg command.