Bull DPX/20, Installing And Maintaining

Page: 35 / 69

4–1
Chapter 4. Upgrading and repairing a storage system
4 Upgrading and repairing a storage
system
You upgrade a storage system by adding optional modules that are
customer-replaceable units (CRUs). You repair a storage system by replacing faulty
CRUs. You can add or replace the following CRUs while the storage system is
powered up:
D
Disk modules
D
Voltage semi-regulated converters (VSCs)
D
Fan modules
When the storage system is powered down, you can also replace the storage control
processor (SP) and its memory modules (SIMMs), the write-cache memory card and
its battery, the external SCSI bus cables, asynchronous console cable, power cord and
SCSI terminator plug. This chapter describes how to replace all CRUs except the
cables and SCSI terminator plug. For information on where and how to connect them,
see Chapter 2 if the storage system is the only one on the SCSI bus, and Chapter 3 if
the storage system is one of several on the SCSI bus.
Two status lights – the green system power light and the amber system service light –
are visible from the front of the chassis. The system service light is on when the SP,
disk drive modules, VSCs, and fan modules are powered up. The system service light
is on when the SP or VSC detects a hard or logical fault in the chassis. If it is on, you
should check all CRUs to see if any has its fault light lit, indicating that you should
replace it.
If
none
of the fault or service lights on the CRUs are lit, the write-cache
memory card needs replacing.
Location of the CRUs and system status lights in the disk-array storage system
A0
B0
A1
B1
B2
A3
A2
Back view Front view
7 Disk-drive
modules
Storage-control
processor (SP)
VSC A
VSC B
SCSI bus
cables
ac power cord
Asynchronous
cable (optional)
3 Fan
modules
System
power light
System
service light
Write-cache
memory card