11.1.2 How to Recover From Power Loss (SSVM or CVM)

Power failures can detach disk drives and cause plexes to become detached, and thus, unavailable. In a mirror, however, the volume remains active, because the remaining plex(es) in the volume are still available. It is possible to reattach the disk drives and recover from this condition without halting nodes in the cluster.

These are the high-level steps to recover from power loss to a SPARCstorage Array in an SSVM configuration:

• Determining the errored plex(es) by using the vxprint and vxdisk commands

• Fixing the problem that caused the power loss

• Running the drvconfig and disks commands to create the /devices and /dev entries

• Scanning the current disk configuration

• Reattaching disks that had transient errors

• Verifying there are no more errors

• (Optional) For shared disk groups, running the vxdg command for each disk that was powered off

• Starting volume recovery

These are the detailed steps to recover from power loss to a SPARCstorage Array in an SSVM configuration.

1. Run the vxprint command to view the errored plexes.

   Optionally, specify a disk group with the -g diskgroup option.

2. Run the vxdisk command to identify the errored disks.

   # vxdisk list DEVICE TYPE DISK GROUP STATUS .. - - c1t5d0 toi failed was:c1t5d0s2 ...

3. Fix the condition that resulted in the problem so that power is restored to all failed disks.

   Be sure that the disks are spun up before proceeding.

4. Enter the following commands on all nodes in the cluster.

   In some cases, the drive(s) must be rediscovered by the node(s).

   # drvconfig # disks

5. Enter the following commands on all nodes in the cluster.

   SSVM or CVM must scan the current disk configuration again.

   # vxdctl enable # vxdisk -a online

6. Enter the following command on all nodes in the cluster.

   ---

   Note -

   For CVM, enter the command first on the master node, then on the slave nodes.

   ---

   This will reattach disks that had transitory failures.

   # vxreattach

7. Verify the output of the vxdisk command to see if there are any more errors.

   # vxdisk list

   If there are still errors, rerun the vxreattach command as described in Step 6.

8. (CVM only) If you have shared disk groups, and if media was replaced from the master node, repeat the following command for each disk that has been disconnected.

   The physical disk and the volume manager access name for that disk must be reconnected.

   # vxdg -g disk-group-name -k adddisk medianame=accessname

   The values for medianame and accessname appear at the end of the vxdisk list command output.

   For example:

   # vxdg -g toi -k adddisk c1t5d0=c1t5d0s2 # vxdg -g toi -k adddisk c1t5d1=c1t5d1s2 # vxdg -g toi -k adddisk c1t5d2=c1t5d2s2 # vxdg -g toi -k adddisk c1t5d3=c1t5d3s2 # vxdg -g toi -k adddisk c1t5d4=c1t5d4s2

   You can also use the vxdiskadm command, or the graphical user interface, to reconnect the disks.

9. From the node, or from the master node for shared disk groups, start volume recovery.

   # vxrecover -bv [-g diskgroup]

10. (Optional) Run the vxprint -g command to view the changes.