48 Planning: MD3200i Series Storage Array Terms and ConceptsNOTE: Setting a high priority level impacts storage array performance. It is notadvisable to set priority levels at the maximum level. Priority should also beassessed in terms of impact to host server access and time to complete anoperation. For example, the longer a rebuild of a degraded virtual disk takes, thegreater the risk for potential secondary disk failure.Virtual Disk Migration and Disk RoamingVirtual disk migration is moving a virtual disk or a hot spare from one array toanother by detaching the physical disks and re-attaching them to the newarray. Disk roaming is moving a physical disk from one slot to another on thesame array.Disk MigrationYou can move virtual disks from one array to another without taking thetarget array offline. However, the disk group being migrated must be offlineprior to performing the disk migration. If the disk group is not offline prior tomigration, the source array holding the physical and virtual disks within thedisk group marks them as missing. However, the disk groups themselvesmigrate to the target array.An array can import a virtual disk only if it is in an optimal state. You canmove virtual disks that are part of a disk group only if all members of the diskgroup are being migrated. The virtual disks automatically become availableafter the target array has finished importing all the disks in the disk group.When you migrate a physical disk or a disk group from one MD3200i array toanother, the MD3200i array you migrate to, recognizes any data structuresand/or metadata you had in place on the migrating MD3200i array. However,if you are migrating from any device other than a MD3200i Series StorageArray, the MD3200i array does not recognize the migrating metadata andthat data is lost. In this case, MD3200i initializes the physical disks and markthem as unconfigured capacity.NOTE: Only disk groups and associated virtual disks with all member physical diskspresent can be migrated from one storage array to another. It is recommended thatyou only migrate disk groups that have all their associated member virtual disks inan optimal state.NOTE: The number of physical disks and virtual disks that a storage array supportslimits the scope of the migration.
