14.13 Increasing the Size of a Software RAID Device

You can increase the capacity of an existing software RAID 0, 1 or 5 device by adding partitions, up to the maximum number for the type of RAID. You cannot modify the size of an individual partition after the device is created.

IMPORTANT:If the software RAID device is shared in a cluster, connect to the node where the RAID is currently active to manage the RAID and increase the size of the RAID.

To add partitions to an existing software RAID:

  1. In iManager, click Storage > Software RAIDs.

    For instructions, see Section 10.1.5, Accessing Roles and Tasks in iManager.

  2. Select a server in the eDirectory tree where you are logged in.

    For instructions, see Section 10.1.6, Selecting a Server to Manage.

  3. Make sure that there is no I/O for the volumes on the RAID device by deactivating the volume.

    1. Click Volumes.

    2. Select the volumes in the RAID device you want to expand.

    3. Click Dismount.

  4. Select a device in the Software RAID Devices list.

    If the device contains the maximum number of partitions, the Increase Size option is dimmed. You cannot expand the RAID. Do not proceed.

  5. Click Increase Size.

    This opens the Expand a RAID Wizard to let you choose from available free space on devices that are not already members in the RAID and that contain enough free space to meet the RAID’s current partition size.

  6. Do one of the following:

    • If there are no devices available, you cannot expand the RAID. Click Cancel.

      A device must be the same size or larger than the segment size being used in the RAID. You might need to add or initialize a new device, then try again.

    • Select the check box next to each of the storage devices you want to obtain space from.

      The partition size is predetermined by the existing RAID. The partition you choose must be the same size as other partitions comprising the device.

      Stripe size is fixed at its current value for the duration of the expansion. If you want to change the stripe size, restripe after the expansion.

      You can choose multiple partitions up to the maximum for the type of RAID it is. For information, see Determining the Number of Partitions and Determining the Partition Size.

  7. Click Finish.

    After you add a partition, the RAID’s data is restriped across both existing and new partitions. During the restriping, the RAID’s capacity does not include the added partition. While restriping, the new device is considered a failed device until it is completely resynchronized. After the restriping is complete, the RAID’s capacity includes the added partition.

    While expanding a RAID 5 device, if one of the drives goes down (either one of the existing segments or the newly added segment), the pool deactivates. If you remove any device from a RAID 5 other than the one that was just added for restripe, it considers that as a two-disk error, and deactivates the RAID and the pool.

Remirroring and Restriping Temporarily Impacts System Performance

For software RAID 1 devices, the additional mirror begins to collect data immediately. Performance is slightly impacted, but data is available.

For software RAID 0 or RAID 5 devices, the system automatically begins restriping the disks to accommodate the partition you just added. This severely impacts performance until the striping is complete. The capacity of the RAID is not updated until the restriping is done. If the restriping process is interrupted before it completes, it begins automatically on system reboot.