RA8000 and ESA12000 Storage Subsystems
1–22
387404-001
EK–SMCPR–UG. A01
1.4
Storage Device SBBs
The BA370 can accommodate up to twenty-four 3½-inch storage device SBBs
(Figure 1–12). Each occupies one slot (six SBBs per shelf). The SCSI device addresses of
the SBBs can be assigned in the following ways:
•
By the backplane connector
•
With the SCSI device address switch mounted on the rear of the SBB
The HSG80 and the HSZ80 array controllers software product descriptions and release
notes list the subsystem compatible SBBs.
Figure 1–12 Disk Drive SBB
DEVICE
ACTIVITY
(GREEN)
DEVICE
FAULT
(AMBER)
1.5
Power Configuration
There are two primary storage subsystem power configurations:
•
Standard – 4 + 1 power configuration includes one ac power controller and five
power supply SBBs on power bus A
•
Redundant – 4 + 4 power configuration includes one ac power controller and four
power supply SBBs on power bus A, one ac power controller, and four power supply
SBBs on power bus B
When there are less than four operational power supplies, the subsystem will cease
operating to preserve and protect the data. Table 1-2 lists the storage subsystem power
components and configurations.
