Hitachi Universal Storage Platform VM - Manual (Page 29)

Architecture and Components 2-3
Hitachi Universal Storage Platform V/VM User and Reference Guide
DKA DKA
CSW CSW
CMA CMA
SMA SMA
Channel Interface
FC-AL (4 Gbps/port)
Cache Path
SM Path
Max. 60
data drives
Disk Unit
Battery
Box
Battery
Box
Controller Power Supply
Max. 240 data drives per storage system
Drive Path (max. 8 paths)
AC-DC
Power
Supply
Input
Power
AC-DC
Power
Supply
AC-DC
Power
Supply
Power Supply
PDB-Box
PDU
Input
Power
PDB-Box
PDU
AC-DC
Power
Supply
CHA
CHA
CHA
CHA CHA
CHA
Figure 2-2 Universal Storage Platform VM Hardware Architecture
Multiple Data and Control Paths
The Universal Storage Platform V/VM employs the proven Hi-Star™ crossbar
switch architecture, which uses multiple point-to-point data and command
paths to provide redundancy and improve performance. Each data and
command path is independent. The individual paths between the front-end or
back-end directors and cache are steered by high-speed cache switch cards
(CSWs). The USP V/VM does not have any common buses, thus eliminating
the performance degradation and contention that can occur in bus
architecture. All data stored on the USP V/VM is moved into and out of cache
over the redundant high-speed paths.