Article ID: 112842, created on Nov 18, 2011, last review on Jun 17, 2016

  • Applies to:
  • Virtuozzo
  • Virtuozzo containers for Linux 4.6
  • Virtuozzo containers for Windows


Container startup fails with the following error:

C:> vzctl start 101 
Starting container ... 
Parallels Virtuozzo Containers API function call "VZVolumeMountExW" failed (C:\VZ\Private\101\root.efd, {89B53077-4330-4E33-83E9-5F9968F2E13B}) err = 32 
Parallels Virtuozzo Containers API function call "dq_mount" failed 
Cannot set disk quota for container 101 
Cannot mount disk for container 101  

Note!: Error code 32 is important, it distinguishes this issue from any other ones. If you receive a different error code - ignore this article.


During a container operation, the root.efd file can become highly fragmented. NTFS does not release the file control block for highly fragmented files, which prevents the rood.efd file from being mounted.

Microsoft confirmed this issue as a bug, and addressed it in the scope of the LDR Update KB2707576.


To mitigate the issue it's necessary to install update KB2707576, and reboot the hardware node.

If the node cannot be rebooted at the moment you can use attached vzefdunlocker.exe to unlock the container. Below you may find instructions for using the tool:


  1. Download and unpack the attached archive

  2. Open the command prompt and locate vzefdunlocker that was downloaded on the previous step

  3. Run following command:

    C:\>vzefdunlocker.exe <CTID>

    Note!: Replace <CTID> with the actual container ID

    Note!: Do not interrupt vzefdunlocker tool! Execution time depends on root.efd size, thus it might take a while to complete.

  4. Start the container once the tool completes its job

Real-life example:

C:\>vzefdunlocker.exe 1770 
Unlocking the container disk. It will take time depending on the size of the container disk.
The container disk was unlocked successfully.

C:\>vzctl start 1770
Starting container ...
Container is mounted
Container was started

Additional Information

For more help, see:

112845 VZ partition best practices

113728 Issues caused by high fragmentation of root.efd

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