External Ports; External Lu To Be Mapped; External Lu Groups; External Lu Attributes Set By Mapping - HP StorageWorks User Manual

• Configuration of alternate paths (see

External ports

Local disk array ports used for External Storage XP must be set to a designation of External. When the
external disk array is connected to the local disk array's external port via Fibre Channel, you can view
information about the external disk array from Command View XP or XP Remote Web Console. The
external disk array can be connected only to ports designated as External.
To set the port attribute to External, you must release any existing paths currently configured for the port. (If
any paths are still set to a port, its attribute cannot be changed to External.) Before starting External
Storage XP operations, you must know which ports you can change to External.
NOTE: Ports with attributes set for remote copy software (such as RCU Target or Initiator) or other features
cannot be used as external ports for External Storage XP. If the port attribute is set to something other than
External, change its attribute to External. Flex Copy XP and External Storage XP can share an
XP12000/XP10000 port with an attribute of External.
For instructions, see

External LU to be mapped

When connecting an external disk array to a port with an External designation, you can map LUs in the
external disk array (external LUs) as LDEVs in the local disk array (internal XP LDEVs). Verify which LUs in
which external disk array can be mapped as internal XP LDEVs.
You can map only one external LU to a given internal XP LDEV and map up to a theoretical limit of 1,024
external LUs per local disk array port.
An external LU's maximum available capacity depends on the emulation type set when the LU is mapped.
You cannot access data stored in the field over the external LU's maximum available capacity. To set an
emulation type other than OPEN-V, you cannot map external LUs smaller than 38 MB (77,760 blocks). To
set the OPEN-V emulation type, you cannot map external LUs of smaller than 47 MB (96,000 blocks). For
more information about the capacity of the external LU for each emulation type, see
capacity for emulation

External LU groups

When mapping an external LU as an internal XP LDEV, you must register the external LU in an external LU
group.
You can classify external LUs into groups according to their use. The group is called an external LU group
(ExG). For example, you can register several LUs in an external disk array in one external LU group. Or, if
data you want to manage in a chunk is stored in LUs in various external disk arrays, you can register those
LUs in a single external LU group and manage them as a block.
You must assign a number from 1 to 16,384 to each external LU group. For the XP12000 disk array, you
can create a maximum of 15,360 external LU groups. For the XP10000 disk array, you can create a
maximum of 8,192 external LU groups. You can register a maximum of 256 volumes in one external
group.

External LU attributes set by mapping

When mapping an external LU as an internal XP LDEV, use the Add LU pane in External Storage XP to set
the external LU's attributes. For instructions, see
The following are the external LU's attributes:
• Emulation type
Set the mapped LU's emulation type by selecting any emulation type from the drop-down list. However,
if you plan to use the mapped LU for Flex Copy operations, or you plan to access existing data in the
external LU, you must select the OPEN-V emulation type to avoid data resizing.
20 External Storage XP for the XP12000/XP10000
"Alternate
"Setting a local disk array's port
types" on page 112.
paths" on page 22)
attributes" on page 59.
"Mapping external LUs (Add
"Required volume
LU)" on page 60.