DFSR SysVol replication fails daily with Veeam 7
DFSR SysVol replication fails daily. After initiating a D4 authoritative replication DFSR SysVol replication starts working again but fails again the next day with event IDs 4110 and 2109. If you have Veeam in your environment and have recently upgraded to version 7 then read on…
Backing up domain controllers with parallel processing enabled and\or in the same job breaks DFSR SysVol replication.
In this scenario the Veeam jobs have not been changed but Veeam has been upgraded to version 7 and has then had new parallel processing feature enabled.
The issue seems to be caused by Veeam backing up the domain controllers simultaneously.
Currently there is no actual fix for this. Veeam are aware and working on a solution. In the meantime the workaround is to firstly disable parallel processing, for many this is enough to stop Veeam breaking DFSR. However, in my case I had to move one of the domain controllers to a separate job in addition to turning off parallel processing.
Once you have ensured Veeam 7 won’t backup the domain controllers simultaneously you can perform a D4 authoritative replication to get them back in sync. Follow this Microsoft KB if you are unsure how to do this: http://support.microsoft.com/kb/2218556
Parallel processing will enable jobs to run in parallel to better utilise resources and speed up backups. Regardless if you have parallel processing enabled if servers are in the same job then Veeam 7 seems to do a better job of processing the servers in that job simultaneously therefor triggering DFSR to fail.