3-8
Preparing for Universal Volume Manager Operations
Hitachi Universal Storage Platform V/VM Universal Volume Manager User’s Guide
Capacity Guidelines
•
When a volume, which has the capacity of 4 TB or less, in the external
storage system (external volume) is mapped with the setting of OPEN-V
emulation type, the volume is defined as the internal volume that has the
same capacity as the mapped external volume.
External Volume
・
The capacity is 4 TB or less.
・
OPEN-V emulation type
LDEV LU
Figure 3-1
Example of External Volume of 4 TB or Less
•
You cannot access the data that is stored in the field over the maximum
capacity of the external volume. The maximum volume capacity differs
depending on the emulation type that you specify at the external volume
mapping.
•
When an external volume is mapped as internal volume(s) with the setting
of the emulation type other than OPEN-V, the number of volumes and the
volume capacity of the mapped external volume(s) depend on the capacity
of the original external volume and the basic capacity of each emulation
type. When an external volume is mapped with the setting of emulation
type other than OPEN-V, the data management information area is
required to be provided in the mapped volume. This means that the
capacity that can be used after the mapping becomes smaller than the
actual external volume capacity. The available capacity decreases as much
capacity as the data management information area.
Figure 3-2 shows an example of the case that the original capacity of the
external volume is bigger than the basic capacity of the emulation type.
The emulation type is OPEN-3. Figure 3-3 shows an example of the case
that the original capacity of the external volume is smaller than the basic
capacity of the emulation type.
