Hitachi Universal Storage Platform VM - Manual (Page 43)

Architecture and Components 2-17
Hitachi Universal Storage Platform V/VM User and Reference Guide
Data Drive Intermix
All data drives in one array group (parity group) must be of the same capacity
and type. Different drive types can be attached to the same BED pair. All
drives under a single BED pair must operate at the same bus protocol rate,
either 200 or 400 MB/sec, so certain restrictions apply. For example, when an
array group consisting of drives with 200 MB/sec transfer rate is intermingled
with an array group consisting of drives with 400 MB/sec transfer rate, both
array groups operate at 200 MB/sec. Flash drives and disk drives can be
mixed, and the location to install flash drive is not restricted.
Device Emulation Intermix
Figure 2-9 illustrates an intermix of device emulation types. The Universal
Storage Platform V/VM supports an intermix of all device emulations on the
same BED pair, with the restriction that the devices in each array group have
the same type of track geometry or format.
The Virtual LVI/LUN function enables different logical volume types to coexist.
When Virtual LVI/LUN is not being used, an array group can be configured with
only one device type (e.g., 3390-3 or 3390-9, not 3390-3 and 3390-9). When
Virtual LVI/LUN is being used, you can intermix 3390 device types, and you
can intermix OPEN-x device types, but you cannot intermix 3390 and OPEN
device types.
For the latest information on supported LVI and LU types and intermix
requirements, please contact your Hitachi Data Systems account team.
4th
BED
Pair
2nd
BED
Pair
3rd
BED
Pair
1st
BED
Pair
OPEN-3
3390-9
OPEN-V
Array Frame Array Frame
3390-9
3390-3
OPEN-V
Array Frame Array Frame
USP V
Controller Frame
Figure 2-9 Sample Device Emulation Intermix