HP StorageWorks XP Remote Web Console Software - Manual (Page 17)

Each item above is explained in the following sections.
External ports
Local array ports used for XP External Storage must be set to a designation of External. When the
external array is connected to the local array's external port via Fibre Channel, you can view
information about the external array from XP Command View Advanced Edition Software or Remote
Web Console. The external 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. You cannot change the attribute of the port where paths are set to External. Before starting
XP External Storage operations, you must know which ports you can change to External.
Note: You cannot use ports with attributes set for XP Continuous Access Software (such as RCU
Target or Initiator) or other features as external ports for XP External Storage. If the port attribute
is set to something other than External, change its attribute to External. XP Flex Copy and XP
External Storage can share an XP12000/XP10000/SVS200 port with an attribute of External.
For instructions, see Setting a local array's port attributes .
External LU to be mapped
When connecting an external array to an external port, you can map LUs in the external array
(external LUs) as LDEVs in the local array (internal LDEVs). Verify which LUs in which external array
can be mapped as internal LDEVs.
You can map only one external LU to a given internal LDEV and map up to a theoretical limit of
1,024 external LUs per local array port.
Note: A LUN ID of a connected external volume should be set in the range of 0 – 1,023. An
external volume that has a LUN ID equal to or larger than 1,024 cannot be connected.
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
“Required volume capacity for emulation types” (page 160) .
External LU groups
When mapping an external LU as an internal LDEV, you must register the external LU in an external
LU group.
You can classify external LUs set by XP External Storage into groups according to their use. The
group is called an external LU group (ExG). For instance, you can register several LUs in one
external array to one external LU group. Or, if data you want to manage in a chunk is stored in
LUs in various external arrays, you can register those LUs in one 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, you
can create a maximum of 15,360 external LU groups. For the XP10000/SVS200, 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 LDEV, use the Add LU pane in XP External Storage
to set the external LU's attributes. For instructions, see
Mapping external LUs (Add LU) .
Preparing for XP External Storage settings 17