Managing Serviceguard Seventeenth Edition, First Reprint December 2009

Table 4-1 SCSI Addressing in Cluster Configuration
Host Interface SCSI AddressSystem or Disk
7Primary System A
6Primary System B
5Primary System C
4Primary System D
3Disk #1
2Disk #2
1Disk #3
0Disk #4
15Disk #5
14Disk #6
13 - 8Others
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.
Disk I/O Information
Collect the following information for each disk connected to each disk device adapter
on the node:
Bus Type
Indicate the type of bus. Supported busses are Fibre Channel
and SCSI.
Slot Number
Indicate the slot number in which the interface card is
inserted in the backplane of the computer.
Address
Enter the bus hardware path number, which will be seen on
the system later when you use ioscan to display hardware.
Disk Device File
Enter the disk device file name. To display the name use the
ioscan -fnC disk command (for legacy DSFs) or ioscan
-fnNC disk (for agile addressing).
126 Planning and Documenting an HA Cluster