4
Chapter 1: Features of the CHALLENGE RAID Storage System
The CHALLENGE RAID storage system provides a compact, high-capacity,
high-availability source of disk storage for your CHALLENGE S, DM, L, or
XL server system. The storage system offers a large capacity of
high-availability disk storage in multiple disk modules that you can replace
when the storage system is turned on.
The CHALLENGE RAID storage system connects by a small computer
system interface (SCSI-2) differential bus to a SCSI-2 interface in a
CHALLENGE server.
Only Silicon Graphics service personnel authorized to open the computer
cabinet and replace parts should install or replace the SCSI-2 interface. You
can replace the disk modules by following instructions in Chapter 5 in this
guide.
A CHALLENGE server can support multiple CHALLENGE RAID storage
systems. The various storage system configurations, along with their
availability and performance features, are explained in Chapter 2 in this
guide.
The number of CHALLENGE RAID deskside storage systems or rack
chassis assemblies that can be connected on one SCSI bus is limited by the
recommended SCSI bus length limit of 60 feet, as diagrammed in Figure 1-3.
Figure 1-3
Computing SCSI Cable Length Example: Single-Host Configuration
Only
CHALLENGE
RAID
chassis
assembly
3 ft
8 ft
20 ft
RAID
chassis
assembly
8 ft
5 ft
RAID
chassis
assembly
8 ft
5 ft
SCSI differential
terminator
Total length in this example: 57 feet
Recommended maximum length: 60 feet