Hi everybody! Btrfs filesystem could not be mounted because /dev/sdc1 had unreadable sectors. It is/was a single filesystem (not raid1 or raid0) over /dev/sda1 and /dev/sdc1. I wrote the unreadable sectors with hdparm but filesystem still cannot be mounted (sectors were too early perhaps). What should be my next step for recovering the btrfs filesystem? #### Analytically: After # smartctl -t long /dev/sdc I got "Extended offline Completed: read failure 90% 19662 2176" So LBA_of_first_error: 2176 With # hdparm --read-sector I found out that 2176-2183 LBA sectors were unreadable. I wrote them with # hdparm --write-sector and now smartctl does not report any error. However when I run # btrfs fi show I get: Label: 'partition' uuid: c1eb1aaf-665a-4337-9d04-3c3921aa67e0 Total devices 2 FS bytes used 1.53TiB devid 2 size 1.37TiB used 195.00GiB path /dev/sda1 *** Some devices missing #### Complementary Information # uname -a Linux hostname 3.15.5-031505-generic #201407091543 SMP Wed Jul 9 19:44:36 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux # btrfs --version Btrfs v3.12 # btrfs fi show Label: 'partition' uuid: c1eb1aaf-665a-4337-9d04-3c3921aa67e0 Total devices 2 FS bytes used 1.53TiB devid 2 size 1.37TiB used 195.00GiB path /dev/sda1 *** Some devices missing Btrfs v3.12 # btrfs fi df /mnt/partition ERROR: couldn't get space info - Inappropriate ioctl for device ERROR: get_df failed Inappropriate ioctl for device -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html