On Tue, Oct 9, 2018 at 10:47 PM, Shapranov Vladimir <equidam...@gmail.com> wrote: > Hi, > > I've got a filesystem with first ~50Mb accidentally dd'ed. > > "btrfs check" fails with a following error (regardless of "-s"): > checksum verify failed on 21037056 found FC8A6557 wanted 2F51D090 > checksum verify failed on 21037056 found FC8A6557 wanted 2F51D090 > checksum verify failed on 21037056 found 1EDD5E47 wanted 222F7E7F > checksum verify failed on 21037056 found 1EDD5E47 wanted 222F7E7F > bytenr mismatch, want=21037056, have=13515002166904211737 > ERROR: cannot read chunk root > ERROR: cannot open file system > > "mount -o ro /dev/sdf1 /mnt/tmp" fails, while "mount -o ro,subvol=X /mnt/tmp" > succeeds for "/" and couple subvolumes.
What do you get for 'btrfs rescue super -v /dev/sdf1' ? I thought the kernel code will not mount a Btrfs if the first super is not present or valid (checksum match)? -- Chris Murphy
