Purpose

The chvolumegroup command allows you to modify the attributes of an Exascale volume group.

Syntax

chvolumegroup volume-group-ID 
              [ --attributes attribute=value[,attribute=value]... ]

Command Options

The options for the chvolumegroup command are:

• volume-group-ID: Identifies the volume group being changed. You can use the lsvolumegroup command to find the identifier for each volume group.

• --attributes: Optionally specifies attributes to change.

  The following attributes can be changed:

  • name: Specifies the name of the volume group.

  • resourceSharing: Optionally specifies how provisioned resources are shared by volumes in the group. Permitted values are:

    • aggregate: Configures the volume group to share the I/Os per second (IOPS) bandwidth provisioned to each volume in the group. In this case, a volume can exceed its provisioned limit by sharing unused IOPS provisioned to other volumes in the group.

      For example, consider a group with two volumes that are provisioned with 1000 IOPS each. In this example, aggregate resource sharing enables one volume to use 2000 IOPS when the other volume is idle.

    • specified: Configures the volume group to share the I/Os per second (IOPS) bandwidth limit specified by the iopsProvisioned attribute.

    • none: Specifies that the volume group is not a resource-sharing volume group. In this case, each volume is only subject to resource limits imposed at other levels, such as the individual volume level or the Exascale vault level.

  • iopsProvisioned: Optionally specifies the I/O bandwidth limit provisioned to the volume group, expressed in I/Os per second (IOPS).

  • owners: Modifies the volume group owners.

    A volume group can have up to two owners. To modify volume group ownership, you can add or remove one owner at a time.

    To add an owner, specify owners=+user-ID as an attribute setting. To remove an owner, use owners=-user-ID.

    For example, see Example 6-156.

Usage Notes

• When resource sharing is disabled on a volume group (resourceSharing=none), the I/O bandwidth provisioned to the volume group must be zero (iopsProvisioned=0).

• When a volume group uses aggregate resource sharing (resourceSharing=aggregate), the I/O bandwidth provisioned to the volume group must be zero (iopsProvisioned=0).

• When a volume group employs specified resource sharing (resourceSharing=specified), the iopsProvisioned attribute value must be greater than zero.

• A volume must always have at least one owner in common with each volume group it belongs to. Any modification violating this requirement is not permitted.

Examples