On 12/21/2018 10:25 PM, Chris Murphy wrote: > On Thu, Dec 20, 2018 at 3:23 PM Peter Chant <pete@xxxxxxxxxxxxxxx> wrote: >> >> I managed to break my root partition today. Playing with GPU >> passthrough to a second graphics card, unsuccessfully, I suspect lead to >> some lockups and/or unclean mounts. > > Should not matter, in theory. Up until now it has seemed to be rather robust in this respect. Any I don't know if it was an unclean shutdown or something else. I think lesson learned is to have a 'doing' system which I leave alone and a 'play' system that does not cause inconvenience if it breaks. However, that take up extra space and gives two PCs to update... > What do you get for ' btrfs rescue super -v <dev>'? That's a read only > command, I wonder if all the supers are really valid. And if they are, > then I'd like to see 'btrfs insp dump-s -f <dev>' and see if there's a > log tree. And then also the output from 'btrfs check --mode=lowmem > <dev>' which is also read-only, don't use --repair unless a dev > recommends it. > > Had to put the disk into another machine to do this. Results below: btrfs rescue super -v /dev/sdb2 All Devices: Device: id = 2, name = /dev/sdb2 Before Recovering: [All good supers]: device name = /dev/sdb2 superblock bytenr = 65536 device name = /dev/sdb2 superblock bytenr = 67108864 device name = /dev/sdb2 superblock bytenr = 274877906944 [All bad supers]: All supers are valid, no need to recover btrfs insp dump-s -f <dev> superblock: bytenr=65536, device=/dev/sdb2 --------------------------------------------------------- csum_type 0 (crc32c) csum_size 4 csum 0x939edd8c [match] bytenr 65536 flags 0x1 ( WRITTEN ) magic _BHRfS_M [match] fsid 6496aabd-d6aa-49e0-96ca-e49c316edd8e label desk-system generation 7937947 root 1113905790976 sys_array_size 97 chunk_root_generation 7743856 root_level 1 chunk_root 1066627579904 chunk_root_level 1 log_root 0 log_root_transid 0 log_root_level 0 total_bytes 375809638400 bytes_used 352796758016 sectorsize 4096 nodesize 16384 leafsize (deprecated) 16384 stripesize 4096 root_dir 6 num_devices 1 compat_flags 0x0 compat_ro_flags 0x0 incompat_flags 0x6b ( MIXED_BACKREF | DEFAULT_SUBVOL | COMPRESS_LZO | BIG_METADATA | EXTENDED_IREF ) cache_generation 7937937 uuid_tree_generation 7937937 dev_item.uuid d10d601a-54d6-4dce-9e2b-bb90f37c9b84 dev_item.fsid 6496aabd-d6aa-49e0-96ca-e49c316edd8e [match] dev_item.type 0 dev_item.total_bytes 375809638400 dev_item.bytes_used 375808589824 dev_item.io_align 4096 dev_item.io_width 4096 dev_item.sector_size 4096 dev_item.devid 2 dev_item.dev_group 0 dev_item.seek_speed 0 dev_item.bandwidth 0 dev_item.generation 0 sys_chunk_array[2048]: item 0 key (FIRST_CHUNK_TREE CHUNK_ITEM 1066627563520) length 33554432 owner 2 stripe_len 65536 type SYSTEM io_align 65536 io_width 65536 sector_size 4096 num_stripes 1 sub_stripes 1 stripe 0 devid 2 offset 106301489152 dev_uuid d10d601a-54d6-4dce-9e2b-bb90f37c9b84 backup_roots[4]: backup 0: backup_tree_root: 1113909100544 gen: 7937935 level: 1 backup_chunk_root: 1066627579904 gen: 7743856 level: 1 backup_extent_root: 1113909166080 gen: 7937935 level: 2 backup_fs_root: 1113906577408 gen: 7762749 level: 0 backup_dev_root: 1113911820288 gen: 7937933 level: 1 backup_csum_root: 1113909755904 gen: 7937935 level: 2 backup_total_bytes: 375809638400 backup_bytes_used: 352796151808 backup_num_devices: 1 backup 1: backup_tree_root: 1113907347456 gen: 7937936 level: 1 backup_chunk_root: 1066627579904 gen: 7743856 level: 1 backup_extent_root: 1113906987008 gen: 7937936 level: 2 backup_fs_root: 1113906921472 gen: 7937936 level: 0 backup_dev_root: 1113907412992 gen: 7937936 level: 1 backup_csum_root: 1113907658752 gen: 7937936 level: 2 backup_total_bytes: 375809638400 backup_bytes_used: 352796151808 backup_num_devices: 1 backup 2: backup_tree_root: 1113911951360 gen: 7937937 level: 1 backup_chunk_root: 1066627579904 gen: 7743856 level: 1 backup_extent_root: 1113911967744 gen: 7937937 level: 2 backup_fs_root: 1113906921472 gen: 7937936 level: 0 backup_dev_root: 1113907412992 gen: 7937936 level: 1 backup_csum_root: 1113912492032 gen: 7937937 level: 2 backup_total_bytes: 375809638400 backup_bytes_used: 352796151808 backup_num_devices: 1 backup 3: backup_tree_root: 1113907494912 gen: 7937934 level: 1 backup_chunk_root: 1066627579904 gen: 7743856 level: 1 backup_extent_root: 1113907544064 gen: 7937934 level: 2 backup_fs_root: 1113906577408 gen: 7762749 level: 0 backup_dev_root: 1113911820288 gen: 7937933 level: 1 backup_csum_root: 1113907855360 gen: 7937934 level: 2 backup_total_bytes: 375809638400 backup_bytes_used: 352796151808 backup_num_devices: 1 btrfs check --mode=lowmem > <dev> OK, this one threw an error: [1/7] checking root items Error: could not find extent items for root 290 ERROR: failed to repair root items: No such file or directory And then gave this output: Opening filesystem to check... Checking filesystem on /dev/sdb2 UUID: 6496aabd-d6aa-49e0-96ca-e49c316edd8e I'm getting suspicious of the drive as when I was trying the various btrfs rescue * tools I saw a 'bad block', or similar, error displayed. I also have a separate basic install on ext4 on the same disk. Though e2fsck shows no errors and mounts fine I cannot log into that install. Maybe a coincidence, but too many bad things thrown up make me suspicious. Whatever is happening this seems to be really fighting me.
