Dell PowerVault MD3820f - Manual (Page 29)

• Any storage array different from the MD storage array you migrate to (for example, from an MD3460
storage array to an MD3860i storage array), the receiving storage array (MD3860i storage array in the
example) does not recognize the migrating metadata and that data is lost. In this case, the receiving
storage array initializes the physical disks and marks them as unconfigured capacity.
NOTE: Only disk groups and associated virtual disks with all member physical disks present can be
migrated from one storage array to another. It is recommended that you only migrate disk groups
that have all their associated member virtual disks in an optimal state.
NOTE: The number of physical disks and virtual disks that a storage array supports limits the scope
of the migration.
Use either of the following methods to move disk groups and virtual disks:
• Hot virtual disk migration — Disk migration with the destination storage array power turned on.
• Cold virtual disk migration — Disk migration with the destination storage array power turned off.
NOTE: To ensure that the migrating disk groups and virtual disks are correctly recognized when the
target storage array has an existing physical disk, use hot virtual disk migration.
When attempting virtual disk migration, follow these recommendations:
• Moving physical disks to the destination array for migration — When inserting drives 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.
WARNING: Without the interval between drive 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
of the physical disks from the same storage array as a set into the new destination storage array.
Ensure that all of 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 drive 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.
Disk Roaming
You can move physical disks within an array. The RAID controller module automatically recognizes the
relocated physical disks and logically places them in the proper virtual disks that are part of the disk
group. Disk roaming is permitted when the RAID controller module is either online or powered off.
NOTE: The disk group must be exported before moving the physical disks.
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