Administrator Guide

Unless a virtual pool consists exclusively of SSDs, if a virtual pool has more than one disk group and at least one volume that contains data,

the system attempts to drain the disk group to be deleted by moving the volume data that it contains to other disk groups in the pool.

When removing one or more, but not all, disk groups from a virtual pool, the following possible results can occur:

• If the other disk groups do not have room for the data of the selected disk group, the delete operation will fail immediately and a

message will be displayed.

• If there is room to drain the volume data to other disk groups, a message will appear that draining has commenced and an event will be

generated upon completion (progress will also be shown in the Current Job column of the Related Disk Groups table).

○ When the disk group draining completes, an event will be generated, the disk group disappears, and the drives for it becomes

available.

○ If a host writes during the disk group draining, which results in there not being enough room to finish the draining, an event will be

generated, the draining terminates, and the disk group will remain in the pool.

NOTE: Disk group removal (draining) can take a very long time depending on a number of factors in the system,

including but not limited to: large pool configuration; the amount of I/O traffic to the system (e.g., active I/O pages to

the draining disk group); the type of the disk group page migration (enterprise SAS, midline SAS, SSD); the size of the

draining disk group(s) in the system; and the number of disk groups draining at the same time.

If you remove the last disk group in a virtual pool, the system will prompt you to confirm removing the pool, too. If you choose yes, the

pool will be removed. If you choose no, the disk group and the pool will remain.

NOTE: If the disk group is the last disk group for a pool that is used in a peer connection or it contains a volume that is

used in a replication set, the Remove Disk Groups menu option will be unavailable.

Remove a disk group

1. In the Pools topic, select the pool for the disk groups that you are deleting in the pools table. Then, select the disk groups in the

Related Disk Groups table.

NOTE:

To see more information about a pool, hover the cursor over the pool in the table. Viewing pools contains

more details about the Pool Information panel that appears.

2. Select Action > Remove Disk Groups. The Remove Disk Groups panel opens.

3. Click OK.

4. Click Yes to continue. Otherwise, click No. If you clicked Yes, the disk groups and their volumes are deleted, the pool for the disk

groups might be deleted, the disks for the disk groups become available, and the Related Disk Groups table is updated.

Expanding a disk group

You can expand the capacity of a linear disk group, or a virtual disk group with a RAID level set to ADAPT up to the maximum number of

disks that the storage system supports. Host I/O to the disk group can continue while the expansion proceeds. You can then create or

expand a volume to use the new free space that becomes available when the expansion is complete. As described in About RAID levels,

the RAID level determines whether the disk group can be expanded and the maximum number of disks the disk group can have. This task

cannot be performed on an NRAID or RAID-1 disk group.

The following table summarizes disk group types that can be expanded.

Table 17. Disk group expansion

Disk Group Type Expand Available Notes

Linear Yes Excludes NRAD and RAID 1.

Virtual No Add a new disk group to a virtual pool.

ADAPT Virtual or Linear Yes

When expanding a disk group, all disks in the disk group must be the same type (enterprise SAS, for example). Disk groups support a mix

of 512n and 512e disks. However, for best performance, all disks should use the same sector format. For more information about disk

groups, see About disk groups.

Before expanding non-ADAPT disk groups, back up the disk group's data so that if you need to stop expansion and delete the disk group,

you can move the data into a new, larger disk group.

Working in the Pools topic