Chris Murphy - 07.02.19, 18:15: > > So please change the normal behavior > > In the case of no device loss, but device delay, with 'degraded' set > in fstab you risk a non-deterministic degraded mount. And there is no > automatic balance (sync) after recovering from a degraded mount. And > as far as I know there's no automatic transition from degraded to > normal operation upon later discovery of a previously missing device. > It's just begging for data loss. That's why it's not the default. > That's why it's not recommended.
Still the current behavior is not really user-friendly. And does not meet expectations that users usually have about how RAID 1 works. I know BTRFS RAID 1 is no RAID 1, although it is called like this. I also somewhat get that with the current state of BTRFS the current behavior of not allowing a degraded mount may be better… however… I see clearly room for improvement here. And there very likely will be discussions like this on this list… until BTRFS acts in a more user friendly way here. I faced this myself during recovery from a failure of one SSD of a dual SSD BTRFS RAID 1 and it caused me having to spend *hours* instead of what in my eyes could be minutes to recover the machine to a working state again. Luckily the SSDs I use do not tend to fail all that often. And the Intel SSD 320 that has this "Look, I am 8 MiB big and all your data is gone" firmware bug – even with the firmware version that was supposed to fix this issue – is out of service now. Although I was able to bring it back to a working (but blank) state with a secure erase, I am just not going to use such a SSD for anything serious. Thanks, -- Martin
