Mirrored RAID volumes report Resynching status after you restart Windows 7 or Windows Server 2008 R2

Applies to: Windows 7 EnterpriseWindows 7 ProfessionalWindows 7 Ultimate More

Symptoms


After you install a hotfix package on a Windows 7 or Windows Server 2008 R2-based computer, and then you restart the computer, mirrored RAID volumes on the computer report a status of Resynching.

Cause


This issue is caused by the Volsnap.sys driver from the Volume Shadow Copy Service. The software provider driver writes snapshot data to the volumes until the last phase of the system shutdown operation. This may cause volumes that have been mirrored by using the inbox volume manager to go out of sync.

Resolution


Microsoft is aware of this issue and intends to address it in a future release of Windows.

Workaround


To work around this issue, start Registry Editor, and then navigate to the following registry subkey:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\VSS\Settings
Set the following REG_DWORD values to 0:
  • FreeSpacePreCopyPercentage
  • HotBlocksPreCopyPercentage

More Information


The Volume Shadow Copy Service evaluates the integrity of the snapshot data before usage. Therefore, there is no effect on the volume shadow copy. The redundancy of the volume remains intact after the resynchronization of the mirrored volumes is completed.