HP XP External Storage Software - Manual (Page 21)

• How to configure external volume groups (see
“ Registering a Volume to an External Volume Group (ExG) ” on page 21).
• What external volume attributes to be configured (see
“ Configuring External Volume Attributes ” on page 22).
• How to configure cross-subsystem paths (see “ Cross-subsystem Paths ” on page 23).
• How to make volume usable from the local storage system (see
“ Connecting Mainframe Volumes ” on page 29 and section
“ Connecting Open Systems Volumes ” on page 30).
Each item above is explained in the following sections.
Choosing the External Port
The port used for External Storage must be set as the external port. When the external storage system
is connected to the external port of the local storage system, you can view the information on the
external storage system from the Remote Web Console computer. The external storage system cannot be
connected to the ports other than the external port.
In order to set the port attribute to external, the LU paths set to the port must be released. The attribute of
the port where the LU paths are already set cannot be changed to external. Therefore, you must identify
ports whose attributes can be changed to external before starting the External Storage operations.
Note: The ports whose attributes are set for remote copy software (for example, RCU target, initiator)
or other features cannot be used as external ports for External Storage. In addition, change the port
attribute to external if the port attribute is set to other than external.
For instructions on configuring port attributes, see
“ Setting Port Attribute for Local Storage System ” on page 68.
Choosing and Mapping External Volumes
When you connect an external storage system to an external port, volumes in the external storage
system (external volumes) become available for mapping as volumes in the local storage system (internal
volumes). Identify the volumes in each external storage system that should be mapped as internal volumes.
• You cannot access the data that is stored in an external volume beyond the maximum available
capacity.
For example, if an external volume of 100 GB was mapped as an internal volume of 70 GB, then
30 GB of the external volume would not be accessible from the local storage system side.
• You cannot map an external volume whose capacity is smaller than the minimum available
capacity.
For example, you cannot map an external volume of 10 GB as an internal volume which requires
at least 30 GB.
The maximum or minimum available capacity of an external volume depends on the emulation type that is
set when the volume is mapped. See “ Required Volume Capacity for Each Emulation Type ” on page 127
for the capacity of the external volume for each emulation type. For the maximum number of external
volumes which can be mapped, see “ External Storage Requirements ” on page 43.
Registering a Volume to an External Volume Group (ExG)
When you map an external volume as an internal volume, you need to register the external volume
to an external volume group.
External volumes, which are set by External Storage, can be classified into groups by usage. Any group
of this type is called an external volume group (ExG). For instance, you can register multiple volumes
in one external storage system to one external volume group. Or you can register the volumes in one
external volume group and manage them in block, even though the data you want to manage in a lump
is stored in volumes in the different external storage systems.
XP24000 External Storage Software User’s Guide 21