3.9.6.3 Adding and Removing Volumes in a Volume Group

A volume group is a specific collection of Exascale volumes. A new volume group is initially empty and you must separately modify each volume that you want to associate with the group.

To associate an Exascale block volume (or volume clone) with a volume group, use the ESCLI chvolume command and:

• Specify the identifier for the volume you are acting on.

  You can use the lsvolume command to find the identifier for each volume.

• Set the volumeGroup attribute to identify the volume group that you want the volume to be part of.

  You can use the lsvolumegroup command to find the identifier for each volume group.

For example, the following command adds the volume with ID vol0001_96ffd78f28fa475fa4e31cf58c5a00db to the volume group with ID volgrp0001_c2a3cec3a7e7413181fa1730093b3110:

@> chvolume vol0001_96ffd78f28fa475fa4e31cf58c5a00db --attributes volumeGroup=volgrp0001_c2a3cec3a7e7413181fa1730093b3110

If the volume being changed was previously associated with another volume group, then setting the volumeGroup attribute effectively moves the volume from one group to another.

You can also remove a volume from all volume groups by setting the volumeGroup attribute to an empty string. For example:

@> chvolume vol0001_96ffd78f28fa475fa4e31cf58c5a00db --attributes volumeGroup=''

Note the following details about volume groups. Exascale denies any modification to a volume group or associated volumes if it violates any of the specified conditions.

• A volume group can contain only writable volumes, including volume clones. Volume snapshots cannot be part of a volume group.

• All volumes belonging to a volume group must reside in the same Exascale vault.

• A volume must always have at least one owner in common with each volume group it belongs to.

• A volume can be a member of up to five different volume groups. However, at any time, a volume can belong to only one resource-sharing volume group.