HP XP External Storage Software - Manual (Page 30)

Note: If you format the mapped volume of the external storage system from the external storage system
side, the existing data before formatting cannot be assured. When you use the mapped external volume
from the mainframe OS, format the mapped volume from the local storage system side.
For the procedure of the volume formatting operation and the Write to Control Blocks operation, see the
HP StorageWorks XP24000 Virtual LVI/LUN (VLL) and Volume Shredder User’s Guide.
Connecting Open Systems Volumes
Open systems volumes in external storage system connect to and are recognized by the storage system
as open systems volumes, without requiring reformatting. Reformatting is not required because the
connection between the storage system and the external storage system is Fibre Channel. If you need
to initialize the data area for the volume, format the volume using the VLL function. For the procedure
of the volume formatting operation, see the HP StorageWorks XP24000 Virtual LVI/LUN (VLL) and
Volume Shredder User’s Guide.
OPEN-V emulation is recommended because, in most cases, OPEN-V emulation provides the most
efficient use of storage and the best performance. Also, emulation types other than OPEN-V may not
retain existing data after being mapped.
Choosing Mapping Policy
Policy is a list of settings of the necessary information for mapping the external volume. By setting the
mapping policy in advance, the setting at the time of mapping will be easier.
Two policies are prepared in advance. The user can change the default value of the policy. For details on
the default value, see “ Edit Policy Dialog Box ” on page 95.
Difference between Automatic Mapping and Manual Mapping
When you map the external volume, you need to configure:
• cross-subsystem paths
• external volume parameters
• LDEV number to LDEVs in the external volume
• SSID
When you perform automatic mapping, users configure only cross-subsystem paths and all the other
settings above are automatically made by External Storage according to the mapping policy. When you
perform manual mapping, users configure all the settings.
Automatic mapping maps all the external volume found by the Volume Discovery to the internal volumes.
Automatic mapping requires less settings but you are not allowed to set different parameters to each
external volumes or to specify LDEV number to each LDEVs. You can set the parameters such as emulation
type to mapping policy in advance.
For the procedure of automatic mapping, see “
Mapping an External Volume Automatically ” on page 69.
For the procedure of manual mapping, see “ Mapping an External Volume Manually ” on page 69.
Port Discovery and Volume Discovery
Port Discovery and Volume Discovery are the methods used to find external volumes, and will be executed
when you map external volumes or when you add cross-subsystem paths.
Port Discovery is a process to search for and get information about target ports of the connected external
storage system from an external port of the local storage system. The latest information about the external
storage system can be displayed in a dialog box of External Storage when you execute Port Discovery.
You can set in advance the mapping policy on whether to execute the Port Discovery automatically or
manually. If Port Discovery is executed automatically, WWNs connected to all the external ports of the
local storage system will be searched for. If Port Discovery is executed manually, you can select a specific
30 About External Storage Operations