Veritas InfoScale™ 7.1 Release Notes - AIX

Accessing the same LUNs from Client Partitions on different Central Electronics Complex (CEC) modules

This section briefly outlines how to set shared storage so that it is visible from client partitions on different CEC modules.

With the VIO server and client partitions set up and ready, make sure that you have installed the right level of operating system on the client partitions, and that you have mapped the physical adapters to the client partitions to provide access to the external shared storage.

To create a shareable diskgroup, you need to ensure that the different partitions use the same set of disks. A good way to make sure that the disks (that are seen from multiple partitions) are the same is to use the disks serial numbers, which are unique.

Run the following commands on the VIO server (in non-root mode), unless otherwise noted.

Get the serial number of the disk of interest:

$ lsdev -dev hdisk20 -vpd
	hdisk20          
	U787A.001.DNZ06TT-P1-C6-T1-W500507630308037C- 
	L401	0401A00000000  IBM FC 2107

	Manufacturer................IBM
	Machine Type and Model......2107900
	Serial Number...............7548111101A
	EC Level.....................131
	Device Specific.(Z0)........10
	Device Specific.(Z1)........0100
	…

Make sure the other VIO server returns the same serial number. This ensures that you are viewing the same actual physical disk.

List the virtual SCSI adapters.

$ lsdev -virtual | grep vhost
	vhost0  Available  Virtual SCSI Server Adapter
	vhost1  Available  Virtual SCSI Server Adapter

Prior to mapping hdisk20 (in the example) to a SCSI adapter, change the reservation policy on the disk.

$ chdev -dev hdisk20 -attr reserve_policy=no_reserve
hdisk20 changed

For hdisk20 (in the example) to be available to client partitions, map it to a suitable virtual SCSI adapter.

If you now print the reserve policy on hdisk20 the output resembles:

$ lsdev -dev hdisk20 attr reserve_policy
	value
	no_reserve

Next create a virtual device to map hdisk20 to vhost1.

$ mkvdev -vdev hdisk20 -vadapter vhost1 -dev mp1_hdisk5
	mp1_hdisk5 Available

Finally on the client partition run the cfgmgr command to make this disk visible via the client SCSI adapter.

You can use this disk (hdisk20 physical, and known as mp1_hdisk5 on the client partitions) to create a diskgroup, a shared volume, and eventually a shared file system.

Perform regular VCS operations on the clients vis-a-vis service groups, resources, resource attributes, etc.