Losing duplicated files

[lava890]

I’ve had this happen twice in the past couple years so I’d like to see what I can do differently:
 

I have a pool on Windows 10 with about 10 drives. I have folder duplication enabled for several folders. I had a power failure, and it seems one of my 10tb drives got corrupted. When I started the server again, the drive was missing from the pool and was listed as an unpooled drive. There were no folders or files showing up in file explorer, however in drivepool it said that the 8tb that was previously being used by drivepool was “other” and not usable. In file explorer, the space was unavailable as well. I ran chckdsk /r for 15 hours and it found no problems. Scanner found no problems either. I think that file system corruption has occurred but there were no "found.###" folders.

All of the files that were on that drive (duplicated or not) are missing from my pool. How can I prevent this from happening in the future? It seems like drivepool treats the duplicated files as though they were purposely deleted instead of making the pool “read only” until the missing drive is replaced or the duplicated files can be duplicated again. 
 

As a side note, i have a cloud backup of the files and do not have to recover them. 

[Shane]

If a single drive drops from a pool then it should have gone into read-only mode and duplicated files should still be present in the pool, regardless of why the single drive dropped out. If the drive is still present in Explorer / Disk Management and seems to be okay, but is no longer in the pool, DrivePool's metadata (the bit that says "the hidden poolpart folders on drives A, B, C, etc are part of pool X") may have been damaged.

I'd try a Manage Pool -> Re-measure... and if that doesn't help try Cog -> Troubleshooting -> Recheck duplication... and if that doesn't help I'd consider lodging a support ticket with Stablebit since the metadata is supposed to be stored in a triply redundant fashion where possible to prevent this sort of problem.