Managing Serviceguard 14th Edition, June 2007

Planning and Documenting an HA Cluster
Hardware Planning
Chapter 4138
SCSI address must be uniquely set on the interface cards in all four
systems, and must be high priority addresses. So the addressing for the
systems and disks would be as follows:
NOTE When a boot/root disk is configured with a low-priority address on a
shared SCSI bus, a system panic can occur if there is a timeout on
accessing the boot/root device. This can happen in a cluster when many
nodes and many disks are configured on the same bus.
The correct approach is to assign SCSI addresses in such a way that the
interface cards on cluster nodes have the highest priority SCSI
addresses, followed by any boot/root disks that are on the shared bus,
followed by all other disks on the shared bus.
Table 4-1 SCSI Addressing in Cluster Configuration
System or Disk Host Interface SCSI Address
Primary System A 7
Primary System B 6
Primary System C 5
Primary System D 4
Disk #1 3
Disk #2 2
Disk #3 1
Disk #4 0
Disk #5 15
Disk #6 14
Others 13 - 8