HP StorageWorks External Storage XP user guide (T1706-96006, June 2006)

External Storage XP user guide 13
1 Overview of connecting external arrays
External Storage XP realizes the virtualization of storage arrays. You can use External Storage XP to
access multiple storage arrays connected by a Fibre Channel interface as if they were all one storage
array. Once you connect another storage array to an XP array or storage virtualization system using
External Storage XP, you can also use Command View XP or XP Remote Web Console to manage the
data space (but not necessarily the management) of the other storage arrays.
External Storage XP supports external storage LDEVs of any standard XP emulation type, such as OPEN-3,
OPEN-8, OPEN-9, OPEN-L, OPEN-K, OPEN-V, 3390-3, or 3390-0.
NOTE: Currently only the HP StorageWorks XP12000 and XP10000 Disk Arrays and the
HP StorageWorks 200 Storage Virtualization System (SVS200) support external storage.
In this user guide, the original XP12000/XP10000/SVS200 is called the local array and the connected
storage array is called the external array. The volume managed in the local array is called an internal
storage virtualizer LDEV (or internal LDEV), and the volume in an external array is called an external LU.
IMPORTANT: This guide contains information about internal disks or LDEVs. Unlike the
XP12000/XP10000 Disk Arrays, the SVS200 has no internal disks. Therefore, information about internal
disks or LDEVs does not apply to the SVS200.
With the help of host mirroring middleware, Auto LUN XP or HP StorageWorks XP Tiered Storage
Manager, you can use External Storage XP for online or offline data migration, providing a point-in-time
copy of data between an external device and the local array.
Flex Copy XP is another HP StorageWorks product that copies user data between an LU on a local array
and an LU on an external storage device. For a detailed description of Flex Copy XP, see the
HP StorageWorks Flex Copy XP user guide.
External Storage XP features
The following are External Storage XP features:
• Using External Storage XP to map an external LU as an internal LDEV, you can manage the external LU
capacity using Command View XP or XP Remote Web Console as if it were a volume in the local
array.
Mapping means assigning Virtual Devices (VDEVs) and, consequently, Logical Devices (LDEVs) and
host port LUs to external LUs. If you map external LUs as internal VDEVs, you can use Command View
XP or XP Remote Web Console to then assign the VDEV to an internal CU:LDEV and a port/LU
address. This allows you to use an external LU as if it were an LDEV in the local array.
NOTE: The phrases mapped as an internal LU and mapped as an internal LDEV should be
interpreted to mean that the external LU is specifically mapped into the local array as a unique
VDEV (Virtual Device), which is then associated with a local array CU:LDEV (Control Unit:Logical
Device), which is then typically associated with a unique host port/LU combination. Since a local
array LU number is only unique within the name space of a host port (for example, CL1-A),
references to “XP LU” should be interpreted as references to either the unique port/LUN
combination or the unique CU:LDEV combination.
• If you use Flex Copy XP with External Storage XP, you can copy data in the external array to the local
array and copy data in the local array to the external array. For more information about Flex Copy
XP, see the HP StorageWorks Flex Copy XP user guide.