HP StorageWorks XP Remote Web Console Software - Manual (Page 23)

• Ports that can be set to external ports (see “ External ports ” on page 23)
• External array and LUs to map to the internal LDEVs (see “ External LU to be mapped ” on page 23)
• Configuration of external LU groups (see “ External LU groups ” on page 23)
• Configuration of external LU attributes (see “ External LU attributes set by mapping ” on page 24)
• Configuration of alternate paths (see “ Alternate paths ” on page 25)
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
Appendix B .
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
XP External Storage Software User Guide 23