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

Disk group migration allows to you to migrate a disk group by exporting a disk group and then importing it to another storage array. You can also export a disk group to store data offline.

When you export a disk group, all the physical disks become offline. To ensure that the export is successful, at least two physical disks that are not part of the disk group you are migrating must be present in the storage array.

When you migrate the exported disk group to the new storage array, the import fails if a majority of the physical disks are not present in the group. For example, both the physical disks in a two-disk RAID 1 configuration, or three physical disks (one from each disk pair) in a four-disk RAID 10 configuration must be present.