On 12/21/2018 10:25 PM, Chris Murphy wrote:
> On Thu, Dec 20, 2018 at 3:23 PM Peter Chant <[email protected]> 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.
