HP XP External Storage Software - Manual (Page 16)

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.
Figure 1 illustrates a local array and an external array that are connected using External Storage XP
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 External Storage XP. 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 External Storage XP volume from a host
connected directly to the external array. Also, do not access an External Storage XP 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 16