DPM stores everything on a local 20TB RAID (formatted in ReFS). The system was running DPM 2019 a week or so ago and total storage usage was about 11TB. It had been online for several years before I got to it so storage usage was stable.
I upgraded to DPM 2022 since we had to move all the VMs from a 2019 Hyper-V cluster to a 2022 Hyper-V cluster, so we had to update DPM to be able to support the new cluster. I also made some adjustments to the protection jobs, pulling out any old VMs that weren't in use anymore and adding a few "new" servers that weren't currently in DPM.
Within less than a week the storage usage has skyrocketed and the drive is now almost full. I deleted a bunch of old retention points yesterday to get some space back, but DPM went and gobbled most of it up last night.
I am puzzled why the usage is so high for just 10 days' worth of recovery points. The environment that we're backing up isn't big. I have searched for old recovery points that might have been missed the first time around and came up with about 200GB, which is hardly anything. Deduplication isn't an option since the DPM server is physical.
When I checked this morning there were 857GB free on the storage drive. Now (2:40pm) there are just 348Gb free, but the only DPM jobs that have run since this morning are synchronization jobs and Monitoring shows they transferred less than half a GB. So why is DPM showing half a TB gone from free space?
I was wondering if there's some other issue that might be affecting storage usage, perhaps to do with ReFS. Any other ideas would be much appreciated!
