Dropping A Disk From ASM Diskgroup Does Not Remove It From v$ASM_DISK

 

 

Applies to:

Oracle Server - Enterprise Edition - Version: 10.2.0.3
Information in this document applies to any platform.

Symptoms

-- Problem Statement:
After removing the ASM disks from ASM diskgroup and overwrite them using dd command, the disks still appear in the v$ASM_DISK dynamic performance view. Even after adding the disks to another diskgroup, the old disks labels still exists with status of missing in v$ASM_DISK. Restarting the ASM instance did not solve the problem

-- Steps To Reproduce:
1) Drop ASM disks from an existing ASM diskgroup
2) Overwrite the disks using dd command
3) Add the disks to another ASM diskgroup
4) Query the v$ASM_DISK view, old disks labels are still there with status of missing.

-- Business Impact:
This has no effect with the operation of ASM existing and new diskgroups. However, you may want to make sure that v$ASM_DISK contain only up to date data.

Cause

There was a problem with the sun storage system. The ASM Disk was a short time offline. after fixing the problem, two disks in the ASM diskgroup were shown as missing. The 2 disks were dropped and then used to create new diskgroup as indicated above.

Some remaining information still exists in ASM cache and Oracle Cluster Registry (OCR) which is used by  Cluster Synchronization Service  (CSS). The only way to remove them is at least to bounce the ASM instance, and if this is not enough, to restart the CSS (or reboot the machine) to reset the registry information.

Solution

-- To implement the solution, please execute the following steps::
Execute the following command:
1) Shutdown ASM instance
2) Stop Oracle Cluster Synchronization Service Daemon (OCSSD) using
/etc/init.cssd stop
3) Run Oracle Cluster Synchronization Service Daemon (OCSSD) using
/etc/init.cssd run
4) Startup ASM instance and query v$ASM_DISK view and make sure that the problem no longer exists.