BTRFS error ReadyNAS 314, OS6.10.8

Since a drive error is one potential cause, I can't guarantee that destroying and re-creating your volume will fully fix the issue.  It would be good to check the drives out as well.

I actually had this happen twice, now that I think about it.  One was on an EDA500 that had the eSATA cable come loose.  I didn't even mess with it, as what was on it was easily recovered from my backup.  The first time, it was because my UPS battery got too old and didn't hold the unit up during a brown-out.  I was hoping to recover the volume to reduce my recovery work, so I tried a lot of stuff.  Ultimately, I gave up and did the backup (which doesn't take long to update if you've been backing up all along), destroy, and re-creation.  A complete factory default is an even "cleaner" way to accomplish it if you have just the one volume.  If you have "dead" ReadyCloud users accounts, that would clear them, too.  Include backing up the configuration to be restored later.  But if you do have ReadyCloud users, maybe you should see if there seems to be anything in the backup that you don't want restored because it would restore the ReadyCloud accounts.