Compex Systems Advanced SerialRAID Adapters SA33-3285-02 - Manual (Page 29)

Simple Loop — One Disk Drive Missing
If a disk drive fails, or is switched off, the loop is broken, and one of the data paths to a
particular disk drive is no longer available. The disk drives on the remainder of the loop
continue to work, but an error is reported to the system. The adapter now uses the
alternative path to some of the devices.
In Figure 3, disk drive number 3 has failed. Disk drives 1 and 2 can communicate with
the using system only through connector A1 of the SSA adapter. Disk drives 4 through
8 can communicate only through connector A2 of the SSA adapter.
Using system
Disk
1
Disk
2
Disk
3
Disk
4
Disk
5
Disk
6
Disk
7
Disk
8
A1 A2 B1 B2
Figure 3. Simple Loop with One Disk Drive Missing
Chapter 2. Introducing SSA Loops 9