Troubleshooting: DPM volumes are flagged as missing and VolSnap logs event ID 86

Hi everyone, Marc Reynolds here. I have seen some issues recently where DPM volumes are flagged as “missing” in the DPM console so I wanted to take a minute and show you an easy way to fix this.

Symptoms

In System Center Data Protection Manager, DPM volumes are showing as missing. In the DPM admin console (MMC) under Management\Disk, the storage pools disks have a red "x". In Disk Manager the disks have a status of "Errors" and the volumes are listed as "Healthy at Risk". The option to reactivate the disks is grayed out.  In addition, the system event log may contain the following volsnap error:

Log Name: System
Source: volsnap
Date: 
Event ID: 86
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Computer: DPMServer.domain.com
Description:
Volume C:\...es\Microsoft DPM\DPM\Volumes\Replica\File System\vol_79ec325a-145d-4bfc-a089-68fed8e0aeed is offline for shadow copy protection. A read or write failure to shadow copy storage occurred. Please ensure that the shadow copy storage is still present in the system. Please try clearing the protection fault or restart the computer. If all else fails, revert out of shadow copy protection mode to reclaim the use of the volume while losing the shadow copies.

Cause

Disk I/O errors have caused the disk to log errors and the volumes to be flagged as "Healthy at Risk". DPM checks the status of the volumes and if it finds a volume in any state other than "Healthy" it reports the volume as missing and the DPM jobs linked to that volume will fail.

Resolution

1. Stop DPM
2. In Disk Manager right click on the disk(s) with "Errors" and take it offline
3. Once the disk is offline, right click and bring it back online
4. Once it comes online, the volumes should now show as "Healthy" and the volume missing errors will no longer be present in DPM.

If any of the volumes are showing up in Disk Manager as "Raw" you will need to bring them out of Shadow Copy Protection mode using vshadow-x64.exe

Marc Reynolds | Senior Support Escalation Engineer

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