The VSS Writer encountered problems communicating with one or more Hyper-V guests

Error code

Product

Applies to

BA731

BackupAssist

BackupAssist v7.2.2 and later

Description

The VSS Writer encountered problems communicating with one or more Hyper-V guests. The backups of the effected guests may be in an inconsistent state.

Resolution

The warning you received in BackupAssist will contain a list of Hyper-V guests that are failing to comply with the VSS Writer's command to prepare for a backup.

1. Connect to the host and each of the guests listed and view the Microsoft-Windows-Hyper-V-VMMS / Admin section of the System Events Log, on the Hyper-V Server side.

2. Check any errors around the time of the backup on both the guest and the host. This information will help determined why the Hyper-V guest was not engaged by the VSS Writer. The steps required to resolve the problem will depend on its cause, as reported in the log.

If there are no VSS related entries then the Hyper-V guest was not receiving the VSS-Writers commands to prepare for a backup. This could be due to the Integration Services being obsolete, or not being installed on the Hyper-V guest.

Identifying the guest/s

When troubleshooting problems with Hyper-V backups, it is important to first determine which guest/s is causing the error. You can do this by checking the Hyper-V VMSS logs, as shown below. You may also be able to identify the guest from the information in the backup report. If you are not able to identify the guest, try backing up the guests one at a time until the errant guest is found.

The guest causing the error can be confirmed by running the backup again without that guest and checking that the backup runs without errors. You can also try a VSS backup on the guest itself using a trial version of BackupAssist. The success or failure of this backup will help to further narrow down what could be causing the error.

If the problem is with backing up data within a guest, will you need to open the Event Viewer inside that guest and review the VSS log entries. These may identify the exact cause of the VSS error.

  1. Click the Start button.
  2. Click Control Panel.
  3. Click System and Maintenance.
  4. Click Administrative Tools.
  5. Double-click Event Viewer.
  6. In the left hand navigation window, browse to Applications and Services Logs > Microsoft > Windows > Hyper-V-VMMS.

Last updated

Created

Further assistance

8th Jan 2018

28th Aug 2013

BackupAssist Support page