BMR backup fails in Data Protection Manager or Azure Backup Server

Applies to: System Center 2016 Data Protection Manager


When you perform a bare metal recovery (BMR) backup by using Microsoft Azure Backup Server (MABS) or System Center Data Protection Manager (DPM), the backup fails. You receive one of the following error messages on the DPM server:


The following error entries are logged on the protected server:



Windows backup server writes directly to the DPM or MABS share during backup. This issue occurs if the I/O latency is greater than the standard SMB time-out (4560 seconds).


Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, see How to back up and restore the registry in Windows.

To fix the issue, follow these steps:

  1. On the protected server, open Registry Editor, and then add the SessTimeout registry entry as shown under the following subkey: 

    Note The 1,200 seconds (20 minutes) time-out is a recommended value. Adjust the value as appropriate. You can review the Resilient File System (ReFS) event logs on the DPM or MABS server to find any suspected I/O latency.

  2. Restart the protected server.

    If you can't restart the protected server, stop and restart the Workstation (Lanmanworkstation) service.

    Note Make sure that you check the list of dependencies for the Workstation (Lanmanworkstation) service. The services that depend on this service must also be restarted.

More information

When you use BMR backup, make sure that the following prerequisites are met: