HP StorageWorks XP Remote Web Console Software - Manual (Page 14)

Command View Advanced Edition Software or 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 XP Flex Copy with XP External Storage, 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 XP
Flex Copy, see the HP StorageWorks Flex Copy XP user guide.
Figure 1 illustrates a local array and an external array that are connected using XP External Storage
and Fibre Channel hardware. In Figure 1 , the external array is connected to the external port of the
local array via a switch (or hub) using a Fibre Channel interface. External is a local array port attribute
used for XP External Storage. In
Figure 1 , external LUs are mapped as local array VDEVs and LDEVs
and, consequently, as an LU.
NOTE:
Do not access any external storage volume that is mapped as an XP External Storage volume from a
host connected directly to the external array. Also, do not access an XP External Storage mapped
external array volume using the external array's functions (for example, local replication). After
mapping an external LU as a local array volume, access the mapped external LU only from the local
array.
NOTE:
Except on the MSA, a host can directly access external array volumes that have not been mapped as
local array volumes.
Overview of connecting external arrays 14