Product manual

CDA 7 5630 Product Manual
5-8 77 A1 69UP Rev00
In the following examples, disk director 1 and disk director 2 are paired. Each
CDA 7 disk director services 16 disk devices.
E
XAMPLE 1:
Disk director 1 fails. Disk director 2 automatically performs any I/O operations
with all of the devices normally serviced by disk director 1 as well as all its own
disk devices with no interruption in processing.
❑
E
XAMPLE 2:
On disk director 1, processor A, primary SCSI bus C fails. On disk director 2,
processor B, primary SCSI bus D fails. The devices of these failing buses are
serviced as follows:
• The devices of failing bus C, are serviced by disk director 2, processor A,
secondary SCSI bus C.
• The devices of failing bus D are serviced by disk director 1, processor B,
secondary SCSI bus D.
The functioning primary buses on each of the disk directors continue to service
their respective devices.
❑
E
XAMPLE 3:
On disk director 2, processor A, primary SCSI buses C and D fail. The devices of
these failing buses are serviced as follows:
• The devices of failing bus C are serviced by disk director 1, processor A,
secondary SCSI bus C.
• The devices of failing bus D are serviced by disk director 1, processor A,
secondary SCSI bus D.
The functioning primary buses of disk director 2 continue to service their
respective devices.