Dell PowerVault ME4 Series Storage System Administrator’s Guide

Resolving a pool conflict caused by inserting a foreign disk group

If you insert a virtual disk group from an old system into a new system, the new system attempts to create a virtual pool for that disk group. If that system already has a virtual pool with the same name, the pool for the inserted disk group will be offline. For example, if the new system has a pool A and you insert a disk group that came from pool A on the old system, the imported pool A from old system will be offline.

This type of operation is not common, and you should consider your conflict resolution options carefully. To resolve this conflict, do either of the following:

• If the pool conflict was expected—for example, you want to access data on the disk group from pool A of the old system:
  1. Unmount and unmap the LUNs from any host accessing volumes on the new system.
  2. Stop I/O from hosts accessing any volumes on the new system and power down the new system.
  3. Physically remove all disks for the original pool A of the new system.
  4. Insert the disks from pool A of the old system.
  5. Restore power to the new system. The data on the disk group from pool A of the old system is now accessible.
  6. Copy that data to pool B on the new system.
  7. After you have copied the data to the new system, remove the disks from old system and reinsert the disks from the new system.
  8. Remap and remount the LUNs to any host that requires access to volumes on pool A of the new system.
     CAUTION:This type of operation must be performed offline. Removing a virtual disk group or pool while the system is online may result in corruption and possible data loss. The system must be powered off before any disks are removed.
• If the pool conflict was unexpected—for example, you did not realize that there was a previous pool on the disks of the old system and data that is contained on the disks is no longer needed:
  1. Remove the disks that were from the old system out of the new system.
  2. Put the disks back into the old system.
  3. From the old system, delete the pool off the disks.
     CAUTION:Deleting a pool deletes all the data that it contains.
  4. Reinsert the disks into the new system.

     The disks from the old system now show as available and can be added to an existing pool on the new system.

If you are unable to find a pool with a duplicate name, or are unsure of how to safely proceed, download logs from the system, and contact technical support for assistance.