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. I can even ls the root directory, but at some point something can't be read anymore and following errors appear in dmesg: [385647.999981] btrfs_dev_stat_print_on_error: 158686 callbacks suppressed [385648.079187] BTRFS error (device sdd1): bdev /dev/sdf1 errs: wr 0, rd 22094847, flush 0, corrupt 0, gen 0 [385648.193733] BTRFS error (device sdd1): bdev /dev/sdf1 errs: wr 0, rd 22094848, flush 0, corrupt 0, gen 0 Also it is worth mentioning that after corruption one of the subvolumes was mounted read-write and possibly some files were written. Is there any chance to recover the FS? -- Best regards, Vladimir
