Preparing for Universal Volume Manager Operations 3-9
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
VDEV LDEV LU
6 GB
Area provided to store data
management informat ion
Free Space
(The area les s than the basic
capacity of emulation type
remains as free space)
OPEN-3
External Volume

Figure 3-2 When the External Volume Capacity is Bigger than the

Basic Capacity of Specified Emulation Type (Example of

the OPEN-3 emulation type)

VDEV LDEV LU External Volume
2 GB Area provided to store data
management informatio n

Figure 3-3 When the External Volume Capacity is Smaller than the

Basic Capacity of Specified Emulation Type

Guidelines for Mainframe Volumes
�� If you plan to use the mapped external volume from the mainframe OS
(e.g., the volume is mapped with the setting of 3390-x mainframe
emulation type), you need to select the external volume that consists of
one LDEV or you need to adjust the capacity of the external volume to be
mapped beforehand.
• If multiple LDEVs exist in one external volume and if a lot of I/Os are made
to these LDEVs, the read, write commands may become timeout. When the
commands become timeout, the SIM (21D2xx) is reported.