Categories: Active Directory

DFSR no longer replicates files

This article discusses an issue where, after restoring a virtualized server’s snapshot, the Distributed File System Replication (DFSR) service fails to replicate files. You may create a guest snapshot of a server that is using DFSR to replicate files using any virtualization tool. The server is later restored to that earlier time when you use that snapshot. On the server that has been restored, you see the following behaviours:

After a period of time during which no inbound nor outbound file replication occurs, DFSR events 5014 and 5004 are reported, indicating that replication has resumed.
Any files added, removed, or altered following the snapshot but before the restoration duplicate inbound.
After the restoration, no new or altered data are replicated outside.
No matter how recent, updates to files on partner servers will be replicated inward, overwriting any local modifications and perhaps losing more recent data.
The DFSR databases will eventually automatically rebuild and record failures and warnings in the event log. Following a successful rebuild, DFSR will once more record internal issues and rebuild the database.

Log Name: DFS Replication
Source: DFSR
Date: <DateTime>
Event ID: 2212
Task Category: None
Level: Warning
Keywords: Classic
User: N/A
Computer: DC12.windowstechno.local Description: The DFS Replication service has detected an unexpected shutdown on volume C:. This can occur if the service terminated abnormally (due to a power loss, for example) or an error occurred on the volume. The service has automatically initiated a recovery process. The service will rebuild the database if it determines it cannot reliably recover. No user action is required. Additional Information: Volume: C: GUID: <GUID> Log Name: DFS Replication Source: DFSR Date: <DateTime> Event ID: 2104 Task Category: None Level: Error Keywords: Classic User: N/A Computer: DC12.windowstechno.local Description: The DFS Replication service failed to recover from an internal database error on volume C:. Replication has been stopped for all replicated folders on this volume. Additional Information: Error: 9214 (Internal database error (-1605)) Volume: 93404560-E7C8-13MF-BCM2-806E6F6P4563 Database: C:\System Volume Information\DFSR Log Name: DFS Replication Source: DFSR Date: <DateTime> Event ID: 2004 Task Category: None Level: Error Keywords: Classic User: N/A Computer: DC12.windowstechno.local Description: The DFS Replication service stopped replication on volume C:. This failure can occur because the disk is full, the disk is failing, or a quota limit has been reached. This can also occur if the DFS Replication service encountered errors while attempting to stage files for a replicated folder on this volume. Additional Information: Error: 9014 (Database failure) Volume: 93404560-E7C8-13MF-BCM2-806E6F6P4563 Log Name: DFS Replication Source: DFSR Date: <DateTime> Event ID: 2106 Task Category: None Level: Information Keywords: Classic User: N/A Computer: DC12.windowstechno.local Description: The DFS Replication service successfully recovered from an internal database error on volume C:. Replication has resumed on replicated folders on this volume. Additional Information: Volume: 93404560-E7C8-13MF-BCM2-806E6F6P4563 Database: C:\System Volume Information\DFSR

Root Cause

The DFSR database and all other Windows multi-master databases do not allow snapshots. All manufacturers and solutions for virtualization are affected by this absence of support for snapshots. Active Directory Domain Services uses USN rollback quarantine protection, whereas DFSR does not. Snapshots of machines running DFSR on read-write members shouldn’t ever be made or restored in a working setting. As their version vector is not recorded on partners and a USN rollback cannot take place, snapshot restore is only enabled for read-only members.

Resolution

Get in touch with Microsoft Support to address this problem. The remedy entails unique database recovery procedures that may be applied to fix the problematic server without affecting other PCs. Replicating the replication group or replicated folder won’t resolve the problem on the restored server and isn’t a good place to start your investigation. So, that’s all in this blog. I will meet you soon with next stuff .Have a nice day !!!