Volume Revert: Volume dismounted during revert operation

During a shadow copy revert operation, both the volume being reverted and the volume containing the shadow copy storage area (also referred to as the Diff Area) must be available. If either volume becomes unavailable, then the revert process will stop and will only restart when both volumes are available again.

Cause

Either the volume being reverted or the volume containing the Diff Area was unavailable during the shadow copy revert operation.

Check connectivity issues relating to the disks that contain those volumes. The revert process will restart when those volumes are available again.