Hi, the investigation of damaged root trees are already discussed in the thread starting with https://www.spinics.net/lists/linux-btrfs/msg74019.html However, one point wasn't discussed at the end: > I thought so too. Is there a reason why they ended up being colocated? > I'm surprised with all the redundancies btrfs is capable of, this can > happen. Was it because the volume was starting to become full? (This > whole exercise of turning on mirroring was because we're migrating to > bigger disks) Because I have the same issue on an embedded system, after a power cut, where none of the root tree copies are usable anymore, I'd also like to know : - How can we end up in that recoverable state? - Why can't we protect the fs against the unrecoverable state? - Why is that error is so hard to recover? Furthermore, I'd like to know what would be the best solution for an embedded system where power cuts are unavoidable (because of a missing circuit). I'm thinking of using a read-only rootfs with a separate data partition to ensure at least a booting system. But anyway, the data partition could end up in the same state. I'm not sure if it would be also a good option working with snapshots. My space on the embedded device is limited to 8GB. The OS already takes about 4GB. Best regards Carsten
