Hi, On Sun, May 10, 2020 at 10:52 AM Christoph Heinrich <chheinml@xxxxxxxxx> wrote: > > Hello, > > > > my hard drive can't be mounted anymore. > > Two days ago the drive was very slow (<1kb/s read and write, but I didn't find any errors anywhere). > > However after unplugging and plugging in again, everything seemed normal again, so I don't know if that's related. If you were using 5.6.x at the time of this, the tree checker should stop things on write if there's a problem, before there's corruption. It's possible there's previously existing corruption. > > When trying to mount it today I get that error: > > > > mount: /mnt: wrong fs type, bad option, bad superblock on /dev/sdb, missing codepage or helper program, or other error. > > > > Mounting without -o results in dmesg: > > > > [14479.650956] BTRFS info (device sdb): disk space caching is enabled > > [14479.650963] BTRFS info (device sdb): has skinny extents > > [14499.742007] BTRFS error (device sdb): parent transid verify failed on 3437913341952 wanted 7041 found 6628 > > [14499.753076] BTRFS error (device sdb): parent transid verify failed on 3437913341952 wanted 7041 found 6628 > > [14499.753089] BTRFS error (device sdb): failed to read block groups: -5 > > [14499.816157] BTRFS error (device sdb): open_ctree failed > > > > I already tried mounting with usebackuproot,nospace_cache,clear_cache, but that resulted in the same error messages as before. > > > > When running btrfs check I get the output: > > parent transid verify failed on 3437913341952 wanted 7041 found 6628 > > parent transid verify failed on 3437913341952 wanted 7041 found 6628 > > parent transid verify failed on 3437913341952 wanted 7041 found 6628 > > Ignoring transid failure > > ERROR: child eb corrupted: parent bytenr=3437941538816 item=123 parent level=2 child level=0 > > ERROR: failed to read block groups: Input/output error > > ERROR: cannot open file system > > > > From what I've read so far, running btrfs-zero-log or btrfs check --repair may help, > but it may also do more damage then good, so I'd rather ask then make the situation worse then it already is. What do you get for: # btrfs insp dump-s /dev/ # btrfs insp dump-t -b 3437913341952 /dev/ # btrfs-find-root /dev/ Those are all read only commands and make no changes to the file system. Also, what are the mount options for this file system in /etc/fstab? > kernel 5.6.11 > > btrfs-progs 5.6 Was this file system ever written to by kernels 5.2.0 - 5.2.14? There was a pretty nasty bug in that range that might be related, but the transid want have difference is bigger than I'd expect for that bug. -- Chris Murphy
