The front of my forehead is now flat from me banging my head on my desk trying to get this working. I have a Supermicro 36 3.5" bay server running an LSI Megaraid 9265-8i card. I've tried multiple RAID setups. I've tried Windows 2008 R2 and Windows 2012.
Right now, the volume is 80TB and DPM 2012 and the local Windows Backup both fail with under 4TB of data on it. I've tried it with just a few test files on it and it still fails. I reformatted the drive, recreated the array, etc. I reinstalled Windows (2008 R2 and then 2012) to see if it was an error with VSS being improperly registered.
If I try to enable Shadow Copies for the volume, I get Error 0x80042306: The shadow copy provider had an error. Event Viewer gives Volume Shadow Copy Service error: Unexpected error DeviceIoControl(volume id) hr=0x80070057.
More poking around tells me that VSS tends to fail on volumes larger than 5TB regardless of the amount of data. Is this true? Does Windows Backup not support large volumes? I mean, their excuse that they use VHD files internally makes sense, but that's why they came out with VHDX...
Does anyone currently back up more than ~10TB on a single volume, and if so, how?