3.9.6.1 Create a Volume Group

A volume group is a specific collection of Exascale volumes.

To create an Exascale volume group, use the ESCLI mkvolumegroup command. For example:

@> mkvolumegroup vol-group1

As shown in the example, the simplest form of the command must specify at least the volume group name (vol-group1). In this case, the volume group is not enabled for resource sharing, because the resourceSharing attribute is set to none by default.

A volume group can optionally be configured as a resource-sharing volume group, using either aggregate or specified resource sharing.

• Under aggregate resource sharing, the volume group automatically shares the total I/Os per second (IOPS) bandwidth provisioned to all volumes in the group. In this case, an individual volume can exceed its volume-level limit by sharing unused IOPS provisioned to other volumes in the group. But the entire group is always governed by the aggregated limit.

  For example:

  @> mkvolumegroup vol-group2 --attributes resourceSharing=aggregate

• With specified resource sharing, a specific IOPS bandwidth limit is associated with the volume group. In this case, the group is governed only by the specified limit.

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

  For example:

  @> mkvolumegroup vol-group3 --attributes resourceSharing=specified,iopsProvisioned=1000

When creating a volume group, you can optionally specify the volume group owners. The value may identify one or two Exascale users that you want to own the volume group. For example:

@> mkvolumegroup vol-group4 --attributes resourceSharing=specified,iopsProvisioned=2000,owners=owner1,owner2

If ownership is not specified, the user creating the volume group is assigned ownership by default.

A new volume group is initially empty and you must separately modify each volume that you want to associate with the group. See Adding and Removing Volumes in a Volume Group.