Mar 05 2023 08:17 PM
The documentation claims that data deduplication is compatible with DFS Replication, but that is not correct. I have several systems with both enabled, some Windows Server 2012 R2 and some Windows Server 2019 systems. If a user interacts with a file that has been deduplicated, such as moving it from one folder to another, DFS-R may log a 4406 error (The DFS Replication service encountered an unsupported reparse point in a replicated folder. This reparse point will not be replicated because the replication of this type of reparse point is not supported by the DFS Replication service.) and delete the file from the partner.
Data deduplication uses reparse points and DFS Replication doesn't like them. I thought that since the documentation says both technologies are compatible that DFS Replication would have been updated to work correctly with reparse points when they are related to data deduplication.
Mar 06 2023 05:20 AM
Mar 06 2023 05:30 AM
Apr 07 2023 02:23 PM
Jun 02 2023 09:19 AM
SolutionIt turns out the March 2023 CU didn't have anything to do with this. Not previously mentioned is that the systems experiencing this problem have Veeam Agent for Windows (VAW) installed. After recently updating VAW to a newer release, the 4406 events returned. The last time the reboot from installing the March 2023 CU must have been what actually fixed things. This time I did a reboot without installing any additional Windows updates and the 4406 events stopped again.
Jun 02 2023 09:19 AM
SolutionIt turns out the March 2023 CU didn't have anything to do with this. Not previously mentioned is that the systems experiencing this problem have Veeam Agent for Windows (VAW) installed. After recently updating VAW to a newer release, the 4406 events returned. The last time the reboot from installing the March 2023 CU must have been what actually fixed things. This time I did a reboot without installing any additional Windows updates and the 4406 events stopped again.