Unable to create quiesced snapshots on Windows virtual machine due to missing VCBRequestor.dll file

 

To work around this issue, manually register the VMware Snapshot Provider.

This issue occurs if the VCBRequestor.dll file is not available in the VMware Tools folder C:\Program Files\VMware\VMware Tools\Drivers\vss\.

To manually register the VMware Snapshot Provider:

1. Click Start > Run, type cmd, and click OK.
2. Enter these commands, in sequence:
   • regsvr32 "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBRequestor.dll"
   • regsvr32 "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBSnapshotProvider.dll"
   • sc delete VMVSS
   • "C:\Program Files\VMware\VMware Tools\COMREG.EXE" -register "C:\Program Files\VMware\VMware Tools\Drivers\vss\VCBSnapshotProvider.dll" "VMware Snapshot Provider" "vmvss" "VMware Snapshot Provider"
     Note: When registering the COM application, you may see an error.
     • If you see this error:
       error 80110801 when attempting to register the COM application
       Delete the VMware Snapshot Provider COM application.
       To delete the VMware Snapshot Provider COM application:
       1. Go to Start > Programs > Administrative Tools > Component Services.
       2. Go to Component Services > Computers > My Computer > COM Applications.
       3. Select VMware Snapshot Provider and press Delete on your keyboard.
       4. Manually register the VMware Snapshot Provider COM application again.
     • If you see this error:
       Error: 0x8000FFFF
       It may indicate registry key corruption. For more information, see Microsoft's Knowledge Base article 940184.
     • Reboot the virtual machine to make the changes effective.

Manually Clearing the ConflictAndDeleted Folder in DFSR

Scenario 1: We need to empty out the ConflictAndDeleted folder in a controlled manner as part of regular administration (i.e. we just lowered quota and we want to reclaim that space).

Scenario 2: The ConflictAndDeleted folder quota is not being honored due to an error condition and the folder is filling the drive.

Let’s walk through these now.

Emptying the folder normally

It’s possible to clean up the ConflictAndDeleted folder through the DFSMGMT.MSC and SERVICES.EXE snap-ins, but it’s disruptive and kind of gross (you could lower the quota, wait for AD replication, wait for DFSR polling, and then restart the DFSR service). A much faster and slicker way is to call the WMI method CleanupConflictDirectory from the command-line or a script:

1.  Open a CMD prompt as an administrator on the DFSR server.
2.  Get the GUID of the Replicated Folder you want to clean:

WMIC.EXE /namespace:\\root\microsoftdfs path dfsrreplicatedfolderconfig get replicatedfolderguid,replicatedfoldername

(This is all one line, wrapped)

Example output:

3.  Then call the CleanupConflictDirectory method:

WMIC.EXE /namespace:\\root\microsoftdfs path dfsrreplicatedfolderinfo where "replicatedfolderguid='<RF GUID>'" call cleanupconflictdirectory

Example output with a sample GUID:

WMIC.EXE /namespace:\\root\microsoftdfs path dfsrreplicatedfolderinfo where "replicatedfolderguid='70bebd41-d5ae-4524-b7df-4eadb89e511e'" call cleanupconflictdirectory

4.  At this point the ConflictAndDeleted folder will be empty and the ConflictAndDeletedManifest.xml will be deleted.

Emptying the ConflictAndDeleted folder when in an error state

We’ve also seen a few cases where the ConflictAndDeleted quota was not being honored at all. In every single one of those cases, the customer had recently had hardware problems (specifically with their disk system) where files had become corrupt and the disk was unstable – even after repairing the disk (at least to the best of their knowledge), the ConflictAndDeleted folder quota was not being honored by DFSR.

Here’s where quota is set:

Usually when we see this problem, the ConflictAndDeletedManifest.XML file has grown to hundreds of MB in size. When you try to open the file in an XML parser or in Internet Explorer, you will receive an error like “The XML page cannot be displayed” or that there is an error at line X. This is because the file is invalid at some section (with a damaged element, scrambled data, etc).

To fix this issue:

1. Follow steps 1-4 from above. This may clean the folder as well as update DFSR to say that cleaning has occurred. We always want to try doing things the 'right' way before we start hacking.
2. Stop the DFSR service.
3. Delete the contents of the ConflictAndDeleted folder manually (with explorer.exe or DEL).
4. Delete the ConflictAndDeletedManifest.xml file.
5. Start the DFSR service back up.

For a bit more info on conflict and deletion handling in DFSR, take a look at:

Staging folders and Conflict and Deleted folders (TechNet)
DfsrConflictInfo Class (MSDN)

WMI and Counters

A

1> Open a command prompt window (Run as Administrator) and change directory (cd) to %windir%\System32\wbem on 32bit Windows or %windir%\SysWOW64\wbem on 64bit Windows
2> Run both these commands one at a time-
a> FOR %i in (*.dll) do RegSvr32 -s %i
b> FOR %i in (*.exe) do %i /RegServer
c> FOR /f %s in ('dir /b /s *.dll') do regsvr32 /s %s
3> Net stop /y winmgmt
4> FOR /f %s in ('dir /b *.mof *.mfl') do mofcomp %s
5> Net start winmgmt

 

B
We need to verify by running any WMI query to check if the WMI is working on the server or not. If the issue is still not resolved, then we need to use the following command to detect and repair a corrupted WMI Repository:
a> rundll32 wbemupgd, RepairWMISetup
b> we need restart the server.

 

C

Open Command Prompt , type lodctr /r and press ENTER. This will repair the pointers

C:\Windows\system32>lodctr/r