Importing an external storage system

You can use image mode volumes to import and migrate existing data that is managed by an external storage system into the system.

You can either use the command-line interface (CLI) or the Storage Migration wizard in the management GUI to migrate data from external storage systems. The Storage Migration wizard simplifies the process by creating the image mode volume of the migrated data, host objects, host mappings, and moving that volume to a storage pool to be managed by the system.

The Storage Migration wizard guides through the appropriate changes to the system. After the migration is complete, remove the external storage system from the system by using the appropriate method for each supported connection type.

If the existing external storage systems do not follow the configuration guidelines, consider completing the data migration away from the image mode volume before you resume I/O operations on the host systems. If I/O operations are continued and the external storage system does not follow the guidelines, I/O operations might fail at the hosts, which might cause loss of access to the data.

The procedure for importing managed disks (MDisks) that contain existing data, depends on the amount of available capacity of the system. You must have the same amount of available capacity in the system as the size of the data that you want to migrate into the system. If you do not have the amount of available capacity, the migration causes the storage pool to have an uneven distribution of data because some MDisks are more heavily loaded than others. Further migration operations are required to ensure an even distribution of data and subsequent I/O loading.

Image mode volumes can be used to migrate existing data from an external storage system. However, they cannot be used to export the replicated volumes to an external storage system. To configure replication on image mode volumes, add volumes to a volume group and then assign a replication policy. Image mode volumes cannot be added to volume groups in a storage partition. A volume group that contains volume with a cache mode other than readwrite, the replication direction cannot be changed.

For more information on image mode volumes, see Volumes.

Importing image mode volumes with an equivalent amount of available capacity

When you import an image mode volume that has a certain gigabytes capacity, and your system has that amount of available capacity in a single storage pool, then:

Follow the Start New Migration wizard in the management GUI.
Select Pools > Import External Storage to import the image mode volumes and to provide an even distribution of data.

Importing image mode volumes with a smaller amount of available capacity

When you import an image mode volume that has a certain gigabytes capacity, and your system does not have that amount of available capacity in a single storage pool, then:

Follow the Start New Migration wizard in the management GUI.
Select Pools > Import External Storage to import the image mode volumes.

Do not select the destination pool at the end of the wizard. If the destination pool is not selected, the system creates the image mode volumes but does not migrate the data away from the image mode volumes. Use volume mirroring or migration to move the data around as you want.