Dell EMC PowerVault MD 34XX/38XX Series Storage Arrays Administrator's Guide

You can move virtual disks from one array to another without taking the target array offline. However, the disk group being migrated must be offline before performing the disk migration. If the disk group is not offline before migration, the source array holding the physical and virtual disks within the disk group marks them as missing. However, the disk groups themselves migrate to the target array.

An array can import a virtual disk only if it is in an optimal state. You can move virtual disks that are part of a disk group only if all members of the disk group are being migrated. The virtual disks automatically become available after the target array has finished importing all the disks in the disk group.

When attempting virtual disk migration, follow these recommendations:

• Moving physical disks to the destination array for migration—When inserting physical disks into the destination storage array during hot virtual disk migration, wait for the inserted physical disk to be displayed in the MD Storage Manager, or wait for 30 seconds (whichever occurs first), before inserting the next physical disk.
  NOTE: Without the interval between physical disk insertions, the storage array may become unstable and manageability may be temporarily lost.
• Migrating virtual disks from multiple storage arrays into a single storage array—When migrating virtual disks from multiple or different storage arrays into a single destination storage array, move all the physical disks from the same storage array as a set into the new destination storage array. Ensure that all the physical disks from a storage array are migrated to the destination storage array before starting migration from the next storage array.
  NOTE: If the physical disk modules are not moved as a set to the destination storage array, the newly relocated disk groups may not be accessible.
• Migrating virtual disks to a storage array with no existing physical disks—Turn off the destination storage array, when migrating disk groups or a complete set of physical disks from a storage array to another storage array that has no existing physical disks. After the destination storage array has been turned on and has successfully recognized the newly migrated physical disks, migration operations can continue.
  NOTE: Disk groups from multiple storage arrays must not be migrated at the same time to a storage array that has no existing physical disks. Use cold virtual disk migration for the disk groups from one storage array.
• Enabling premium features before migration—Before migrating disk groups and virtual disks, enable the required premium features on the destination storage array. If a disk group is migrated from a storage array that has a premium feature enabled and the destination array does not have this feature enabled, an Out of Compliance error message can be generated.