Server 2012 R2 - Deduplication Failure???

I have Data Duplication enabled, and this is the 2nd time this issue has risen, what will happen is randomly (however it seems to be after a veeam backup) one disk seems to de-optimize itself, I cant see any proof of this in the event logs (attached at bottom) but what will happen is 600GB of free space will just disappear overnight.

 

TreeSize Comparison

Fileserver 01 (Affected)

 

FileServer 02 (No Issues) Note how much de-duplication is occurring on dfs-Software, why is Fileserver 01 blowing out? what causes this?

 

To remedy this issue:

  1. I need to expand the disk by a few GB
  2. restart the server
  3. disable de-duplication on the target drive,
  4. restart the server
  5. re-enable de-duplication
  6. run a manual Optimization (start-dedupjob -volume D: -type Optimization
  7. dfs-software folder will eventually go back down to around 8GB of size and also the Chunk store will clear out around 200-300GB.

Due to the large ammount of file changes on disk, after this occurs I need to delete the backups for the fileserver and take a new full backup, as otherwise the next incremental is in excess of 600GB!

After a few minutes it starts the lengthy job of optimizing all the data on the disk and my 600GB of disk space is slowly reclaimed over the course of 8-10 hours.

 

Any ideas where to start looking at root-cause for this? ive been unable to see any triggering events in event log.

Event Logs:Download Eventlogs.zip

 

 

 


September 14th, 2015 8:49pm