HP Serviceguard manual Disk I/O Information, Diskinfo

Table 6 SCSI Addressing in Cluster Configuration	(continued)
System or Disk	Host Interface SCSI Address
Disk #6	14
Others	13 - 8

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).

This information is used in creating the mirrored disk configuration using Logical Volume Manager. In addition, it is useful to gather as much information as possible about your disk configuration. You can obtain information about available disks by using the following commands:

•diskinfo

•ioscan -fnC disk or ioscan -fnNC disk

•lssf /dev/*dsk/*

•bdf

•mount

•swapinfo

•vgdisplay -v

•lvdisplay -v

•lvlnboot -v

•vxdg list (VxVM and CVM)

•vxprint (VxVM and CVM)

These are standard HP-UX commands. See their man pages for complete information about usage. The commands should be issued from all nodes after installing the hardware and rebooting the system. The information will be useful when doing storage group and cluster configuration. You can mark up a printed listing of the output from the lssf command to indicate which physical volume group a disk should be assigned to.

96 Planning and Documenting an HA Cluster