One of the new features that I didn't see listed in all the "Windows Server 2012 r2" posts is that Clustering now supports CSVs that are formatted with ReFS. So, naturally, I would like to change the CSVs where I store the VHDX files to be ReFS. But the VHDX files are being used to store database files in VMs running Sql Server 2012.
The thought is that I would then have RAID at the hardware level, protecting against instantaneous failure. Above that, the real OS (Hyper-V Server 2012 r2) would maintain them as ReFS volumes, which would protect data on those drives against bitrot. Finally, VHDXs are NTFS drives, which means the applications being supported continue to use the filesystem they rely on.
So far, the best I can find is that this is technically supported---because Hyper-V reports that you must turn off the "data integrity" setting in the VHDX file (Set-FileIntegrity cmdlet) when you try to use it from the ReFS volume. But I can't find any more solid information than that. Is it really ready for prime-time, or is it effectively just a tech-preview for clustering?
I found that ReFS only detects bitrot by itself. In order to have ReFS both detect and auto-fix, you must also use Storage Spaces to create a RAID-1 volume using multiple ReFS drives. So it's looking like my solution is evolving into having the hardware RAID present its disks as JBOD, then Windows would take care of the RAID-1 part. I'll be testing if this is a viable setup in Production over the next month or so.