Hitachi MK-96RD626-07 - Manual (Page 26)

2-6 About Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
To use the external volumes, which you mapped as an internal volume (see B
in Figure 2-2), from the host or other program products, the system
administrator needs to create LDEVs in the external volume (see A in Figure
2-2). To create LDEVs, use Universal Volume Manager at the time of mapping,
or use VLL function to an internal volume where an external volume is mapped
after mapping. The LDEVs created by these methods are called “LDEVs in the
external volume” in this document. These LDEVs are usually called “external
volumes” in other documents.
An external volume corresponds to a VLL VDEV (Virtual Device). An LDEV in
the external volume corresponds to a VLL LDEV. Therefore, you can use VLL
function to create custom-sized volumes in an external volume after mapping,
in the same way as creating custom-sized volumes in the normal internal
volumes. For details on VDEVs and LDEVs, see the Virtual LVI/LUN and Volume
Shredder User's Guide.