AIX Tip of the Week

Subject: Recover Procedure for a Failed VIO Disk

Audience: All

Date: November 4, 2005

Here is a recovery procedure for replacing a failed client disk on a Virtual IO server. It assumes the client partitions have mirrored (virtual) disks. The recovery involves both the VIO server and its client partitions. However, it is non disruptive for the client partitions (no downtime), and may be non disruptive on the VIO server (depending on disk configuration). This procedure does not apply to Raid5 or SAN disk failures.

The test system had two Virtual IO servers and an AIX client. The AIX client had two virtual disks (one disk from each VIO server). The two virtual disks were mirrored in the client using AIX's mirrorvg. (The procedure would be the same on a single VIO server with two disks.)

The software levels were:

I simulated the disk failure by removing the client LV on one VIO server. The padmin commands to simulate the failure were:

This caused "hdisk1" on the AIX client to go "missing" ("lsvg -p rootvg"....The "lspv" will not show disk failure...only the disk status at the last boot..)

The recovery steps included:

VIO Server

AIX Client

The "replacepv" command assigns hdisk2 to the volume group, rebuilds the mirror, and then removes hdisk1 from the volume group.

As always, be sure to test this procedure before using in production.

Update - November 10, 2005

AIX Client - Alternative Method

Assuming hdisk1 failed.

Bruce Spencer,

November 4, 2005