I have been using 2012 R2 DPM to protect a 46 TB 2012 R2 deduplicated volume for the past 4 months without too much issue. The volume is a low access archive server. Current usage on the volume is 23 TB (if not deduplicated, this would be more like 38TB). Data transferred during a sync (twice daily) is normally in the order of a few 10's of GB. A Restore Point is set for 12am daily.
However, on Saturday during a scheduled sync, it started to transfer very large amounts of data and got to 9TB before failing early this Monday morning ( it had reached the 90% threshold and couldn't increase the replica volume any more). At first I had thought that
a. There had been a large amount of data suddenly put on the server,
or
b. A lot of files had been changed causing them to be un-deduplicated
However on checking the volume stats ( I have an independent monitoring program), the data usage on the protected volume was fairly static throughout the week at 23 TB - and is still around that now. Besides, nobody generally uses this volume at the weekend.
I am currently running a consistency check on this volume ( this can take 36+ hours), in an attempt to get the sync & restore points working again, however , in the meantime, I need to find out what has caused this.
Has anyone experienced this sort of behavior before ? Where should I start looking ?
DPM version 4.2.1292