As your storage needs increase, you might need to expand a LUN to hold more data.
A good opportunity for expanding a LUN is right after you have expanded your storage system volumes.
Note: A LUN cannot be expanded to more than ten times its original size. Also keep in mind that LUNs with MBR style partitions have a size limit of 2 TB, and LUNs with GBT style partitions have a storage system size limit of 16 TB.
Keep these guidelines in mind when expanding a LUN:
- Understand the storage-management implications of expanding the LUN volume size.
- After you increase the size of a LUN, you cannot reduce it, except by restoring a Snapshot copy made prior to the expansion of the LUN. Such a restore causes the loss of any data added to the LUN after it was expanded. (Conversely, restoring a Snapshot copy of a LUN whose size has since been reduced enlarges the LUN to its former size.)
- If it is necessary to restore a LUN from a Snapshot copy made before the LUN was expanded, you must disconnect the disk using SnapDrive for Windows and then restore the disk from the storage system console. When the LUN is restored, reconnect the disk using SnapDrive.
- When creating a quorum disk, make sure it is the size recommended by Microsoft for your Windows cluster setup. You cannot expand a LUN while it is serving as a quorum. If you need to expand your current quorum disk, you must do one of the following:
- Create a new LUN and designate it as a quorum.
- Create a temporary LUN to serve as a quorum while you expand the old quorum disk. Once the old quorum disk has been expanded, assign it as the quorum for the cluster and delete the temporary quorum.
- While a LUN is being expanded, it might not be available for use. Plan your LUN expansion at a time when applications are less likely to be accessing the LUN.
