This seemed to happen after a power failure. I rebooted and the FS was mounted, but read-only and there were some errors (journalctl not able to start. I did not capture all the errors). I rebooted again and then it wouldn't mount at all. Is there anything else I can do? uname -a Linux sysresccd 3.10.35-std420-amd64 #2 SMP Wed Apr 2 18:31:51 UTC 2014 x86_64 Intel(R) Core(TM) i7-3740QM CPU @ 2.70GHz GenuineIntel GNU/Linux btrfs --version Btrfs v3.14.1 btrfs fi show Label: 'ROOT' uuid: c3117347-03eb-4746-9981-814a32749785 Total devices 1 FS bytes used 605.88GiB devid 1 size 913.00GiB used 754.06GiB path /dev/mapper/vg_crypt-lv_root Btrfs v3.14.1 When I try to mount: mount -o recovery /dev/mapper/vg_crypt-lv_root /mnt/frog mount: wrong fs type, bad option, bad superblock on /dev/mapper/vg_crypt-lv_root, missing codepage or helper program, or other error In some cases useful info is found in syslog - try dmesg | tail or so Output in dmesg: [76286.328518] device label ROOT devid 1 transid 562914 /dev/mapper/vg_crypt-lv_root [76286.329709] btrfs: enabling auto recovery [76286.329714] btrfs: disk space caching is enabled [76286.336555] btrfs bad tree block start 142638070361910812 1107795361792 [76286.336641] btrfs bad tree block start 142638070361910812 1107795361792 [76286.336734] btrfs bad tree block start 142638070361910812 1107795361792 [76286.336945] btrfs bad tree block start 142638070361910812 1107795361792 [76286.337057] btrfs bad tree block start 142638070361910812 1107791572992 [76286.337184] btrfs bad tree block start 142638070361910812 1107791572992 [76286.337198] btrfs: failed to read tree root on dm-2 [76286.337301] btrfs bad tree block start 142638070361910812 1107768221696 [76286.337399] btrfs bad tree block start 142638070361910812 1107768221696 [76286.337409] btrfs: failed to read tree root on dm-2 [76286.337605] parent transid verify failed on 1107746967552 wanted 562911 found 562914 [76286.337812] parent transid verify failed on 1107746967552 wanted 562911 found 562914 [76286.337818] btrfs: failed to read tree root on dm-2 [76286.352774] btrfs: open_ctree failed btrfs-find-root /dev/mapper/vg_crypt-lv_root Super think's the tree root is at 1107748114432, chunk root 1621341777920 Went past the fs size, exiting# This shows 3 bad chunks btrfs rescue chunk-recover -v /dev/mapper/vg_crypt-lv_root ---SNIP--- Bad Chunks: Chunk: start = 0, len = 4194304, type = 2, num_stripes = 1 Stripes list: [ 0] Stripe: devid = 1, offset = 0 Block Group: start = 0, len = 4194304, flag = 2 No device extent. Chunk: start = 4194304, len = 8388608, type = 4, num_stripes = 1 Stripes list: [ 0] Stripe: devid = 1, offset = 4194304 Block Group: start = 4194304, len = 8388608, flag = 4 No device extent. Chunk: start = 12582912, len = 8388608, type = 1, num_stripes = 1 Stripes list: [ 0] Stripe: devid = 1, offset = 12582912 No block group. No device extent. Total Chunks: 758 Heathy: 755 Bad: 3 Orphan Block Groups: Orphan Device Extents: Fail to recover the chunk tree. btrfsck does not run btrfsck /dev/mapper/vg_crypt-lv_root Check tree block failed, want=1107795361792, have=142638070361910812 Check tree block failed, want=1107795361792, have=142638070361910812 Check tree block failed, want=1107795361792, have=142638070361910812 Check tree block failed, want=1107795361792, have=142638070361910812 Check tree block failed, want=1107795361792, have=142638070361910812 read block failed check_tree_block Couldn't setup extent tree Check tree block failed, want=1107745558528, have=142638070361910812 Check tree block failed, want=1107745558528, have=142638070361910812 Check tree block failed, want=1107745558528, have=142638070361910812 Check tree block failed, want=1107745558528, have=142638070361910812 Check tree block failed, want=1107745558528, have=142638070361910812 read block failed check_tree_block Couldn't setup csum tree Check tree block failed, want=1107795329024, have=142638070361910812 Check tree block failed, want=1107795329024, have=142638070361910812 Check tree block failed, want=1107795329024, have=142638070361910812 Check tree block failed, want=1107795329024, have=142638070361910812 Check tree block failed, want=1107795329024, have=142638070361910812 read block failed check_tree_block Checking filesystem on /dev/mapper/vg_crypt-lv_root UUID: c3117347-03eb-4746-9981-814a32749785 Critical roots corrupted, unable to fsck the FS btrfs rescue super-recover -v /dev/mapper/vg_crypt-lv_root All Devices: Device: id = 1, name = /dev/mapper/vg_crypt-lv_root Before Recovering: [All good supers]: device name = /dev/mapper/vg_crypt-lv_root superblock bytenr = 65536 device name = /dev/mapper/vg_crypt-lv_root superblock bytenr = 67108864 device name = /dev/mapper/vg_crypt-lv_root superblock bytenr = 274877906944 [All bad supers]: All supers are valid, no need to recover btrfs-show-super -a /dev/mapper/vg_crypt-lv_root superblock: bytenr=65536, device=/dev/mapper/vg_crypt-lv_root --------------------------------------------------------- csum 0x808ef02b [match] bytenr 65536 flags 0x1 magic _BHRfS_M [match] fsid c3117347-03eb-4746-9981-814a32749785 label ROOT generation 562914 root 1107748114432 sys_array_size 129 chunk_root_generation 562226 root_level 1 chunk_root 1621341777920 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 980326285312 bytes_used 650558619648 sectorsize 4096 nodesize 4096 leafsize 4096 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0xb csum_type 0 csum_size 4 cache_generation 562914 uuid_tree_generation 108092 dev_item.uuid 5c783feb-181c-4bb5-b0af-3c4899c5228f dev_item.fsid c3117347-03eb-4746-9981-814a32749785 [match] dev_item.type 0 dev_item.total_bytes 980326285312 dev_item.bytes_used 809668444160 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 1 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 superblock: bytenr=67108864, device=/dev/mapper/vg_crypt-lv_root --------------------------------------------------------- csum 0x20efd8e5 [match] bytenr 67108864 flags 0x1 magic _BHRfS_M [match] fsid c3117347-03eb-4746-9981-814a32749785 label ROOT generation 562914 root 1107748114432 sys_array_size 129 chunk_root_generation 562226 root_level 1 chunk_root 1621341777920 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 980326285312 bytes_used 650558619648 sectorsize 4096 nodesize 4096 leafsize 4096 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0xb csum_type 0 csum_size 4 cache_generation 562914 uuid_tree_generation 108092 dev_item.uuid 5c783feb-181c-4bb5-b0af-3c4899c5228f dev_item.fsid c3117347-03eb-4746-9981-814a32749785 [match] dev_item.type 0 dev_item.total_bytes 980326285312 dev_item.bytes_used 809668444160 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 1 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 superblock: bytenr=274877906944, device=/dev/mapper/vg_crypt-lv_root --------------------------------------------------------- csum 0xdd688ed4 [match] bytenr 274877906944 flags 0x1 magic _BHRfS_M [match] fsid c3117347-03eb-4746-9981-814a32749785 label ROOT generation 562914 root 1107748114432 sys_array_size 129 chunk_root_generation 562226 root_level 1 chunk_root 1621341777920 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 980326285312 bytes_used 650558619648 sectorsize 4096 nodesize 4096 leafsize 4096 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0xb csum_type 0 csum_size 4 cache_generation 562914 uuid_tree_generation 108092 dev_item.uuid 5c783feb-181c-4bb5-b0af-3c4899c5228f dev_item.fsid c3117347-03eb-4746-9981-814a32749785 [match] dev_item.type 0 dev_item.total_bytes 980326285312 dev_item.bytes_used 809668444160 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 1 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 Thanks, Chris -- 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