ReFS is terrible. We have seen so many customers lose data on ReFS that I started strongly advising everyone against using it. One example: If you (accidentall

ReFS is terrible. We have seen so many customers lose data on ReFS that I started strongly advising everyone against using it. One example: If you (accidentally or on purpose) attach a ReFS disk or LUN to a newer Windows version, it will be silently upgraded to a new ReFS version without any feedback (or chance to prevent it) for the user. No way of attaching the disk on an older Windows version afterwards. But that is not the real problem. The real problem is that the upgrade runs as a separate (user-space) process. If this process crashes or your PC crashes or reboots while it runs, your data is gone. There is no feedback how long it still has to run (we've seen multiple days on large volumes) So yeah, maybe avoid ReFS for a few more years...