Cannot restore files from a Windows virtual machine using deduplication


When restoring from a backup of a virtual machine that runs on Windows Server 2012 or a more recent version of Windows Server, and that has deduplication enabled, a file-level restore completes successfully but only creates stub files.


Windows Server 2012 and more recent versions of Windows Server provide their own native deduplication capability. If a Windows Server VM has native deduplication enabled, file-level restores from backups are not supported because the backed up files are only stored as stubs.


Use one of the following methods to restore files:

  • When using a Virtual Server Agent proxy on Windows Server 2012 or a more recent version of Windows Server with Windows deduplication enabled, use Live File Recovery to restore files that have been dehydrated by Windows deduplication. You must use a MediaAgent that runs Windows Server 2012 R2, or a version of Windows Server that is at or above the version of Windows Server that the guest VM runs. The MediaAgent must have the Virtual Server Agent installed and the Windows deduplication role enabled, and you must specify the MediaAgent as the VSA proxy when you restore the dehydrated files.

    Note: For 11.20 and more recent feature releases, when you restore files for a guest VM that has Windows deduplication enabled, Commvault automatically installs Microsoft deduplication binaries on the Windows MediaAgent (VSA proxy). Deduplication binaries are installed automatically for MediaAgents that run Windows Server 2012 R2 or a more recent version of Windows Server. If the MediaAgent has the Hyper-V role enabled, automatic installation fails, and you must retry the restore using a MediaAgent that does not have the Hyper-V role enabled.

  • To retrieve files from a backup for a Windows Server VM using deduplication, use the Virtual Machine files option on the Restore Options dialog to restore the virtual machine disk that contains the files.
  • Install a local file system agent on the Windows Server VM to enable file-level backups. As a result, the data is backed up in a rehydrated state so that you can restore file-level data from that backup.

Last modified: 5/4/2020 8:51:46 PM