Patent ID: 8554995

Claim:
An apparatus comprising: an external interface port to connect to an external electronic device, the external interface port to communicate over a communications path with the external electronic device according to a serial communication protocol; a storage interface port to connect to a storage subsystem having a plurality of logical storage volumes; and a control device to hide details of the storage subsystem from the external electronic device, the control device configured to: expand a storage capacity of at least one of the logical storage volumes, receive a request to migrate a RAID (Redundant Arrays of Inexpensive Disks) level of the storage subsystem from a first RAID level to a second, different RAID level, in response to receiving the request, wait for hot addition of at least one physical storage device to the storage subsystem; in response to detecting the hot addition of the at least one physical storage device, configure the hot-added at least one physical storage device, and after configuring the hot-added at least one physical storage device, migrate data stored in the storage subsystem that includes the hot-added at least one physical storage device from the first RAID level to the second RAID level.