How to repair errors only found with check --mode=lowmem
The following shows that errors are found with check --mode=lowmem, but are not picked up without lowmem. How would I go about fixing errors only reported by lowmem? [manjaro manjaro]# btrfs check --mode=lowmem --progress /dev/mapper/vg_svelte-home Checking filesystem on /dev/mapper/vg_svelte-home UUID: 93722fa7-7e8f-418a-a7ca-080aca8db94b ERROR: extent[691815358464, 11042816] referencer count mismatch (root: 257, owner: 1869679, offset: 613974016) wanted: 1, have: 2 ERROR: extent[720156536832, 99430400] referencer count mismatch (root: 257, owner: 758215, offset: 1610616832) wanted: 8, have: 379 ERROR: extent[720669147136, 268435456] referencer count mismatch (root: 257, owner: 758215, offset: 4096) wanted: 86, have: 1021 ERROR: extent[720669147136, 268435456] referencer count mismatch (root: 257, owner: 1767807, offset: 4096) wanted: 87, have: 1021 ERROR: extent[726724722688, 64069632] referencer count mismatch (root: 257, owner: 1480823, offset: 99090432) wanted: 1, have: 5 ERROR: extent[737910194176, 134217728] referencer count mismatch (root: 257, owner: 1480726, offset: 268435456) wanted: 1, have: 8 ERROR: extent[738077896704, 134217728] referencer count mismatch (root: 257, owner: 1869696, offset: 402653184) wanted: 5, have: 8 ERROR: extent[744334426112, 268435456] referencer count mismatch (root: 257, owner: 1767802, offset: 0) wanted: 111, have: 294 ERROR: extent[824948670464, 1671168] referencer count mismatch (root: 257, owner: 2000876, offset: 247861248) wanted: 16, have: 26 ERROR: data extent[681550843904 8192] backref lost ERROR: errors found in extent allocation tree or chunk allocation cache and super generation don't match, space cache will be invalidated ERROR: errors found in fs roots found 172094545920 bytes used, error(s) found total csum bytes: 165679768 total tree bytes: 3066789888 total fs tree bytes: 2751315968 total extent tree bytes: 112295936 btree space waste bytes: 568660274 file data blocks allocated: 8158426562560 referenced 597269540864 [manjaro manjaro]# btrfs check --repair --progress /dev/mapper/vg_svelte-home enabling repair mode Checking filesystem on /dev/mapper/vg_svelte-home UUID: 93722fa7-7e8f-418a-a7ca-080aca8db94b checking extents [.] Fixed 0 roots. cache and super generation don't match, space cache will be invalidated checking fs roots [o] checking csums checking root refs found 172091723777 bytes used, no error found total csum bytes: 165679768 total tree bytes: 2003206144 total fs tree bytes: 1687732224 total extent tree bytes: 112295936 btree space waste bytes: 346177995 file data blocks allocated: 5952940838912 referenced 474676633600 [manjaro manjaro]# -- Tom Hale -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: check: "warning line 4144"
On 19/10/17 15:58, Qu Wenruo wrote: > On 2017年10月19日 16:53, Tom Hale wrote: >> In running btrfs check, I got the following message: >> >> warning line 4144 >> >> Could this be a little more descriptive? >> >> * Does it mean I should rebuild my FS from scratch? >> * Is there anything I can do to remove this warning? >> > > --repair is dangerous, use it unless you're sure the problem can be > fixed by it. > > What's the output of "btrfs check" and "btrfs check --mode=lowmem" after > doing the repair? Plain `btrfs check` gives me: checking extents checking free space cache checking fs roots checking csums checking root refs Checking filesystem on /dev/mapper/vg_svelte-home UUID: 93722fa7-7e8f-418a-a7ca-080aca8db94b found 192318169092 bytes used, no error found total csum bytes: 185482112 total tree bytes: 1924104192 total fs tree bytes: 1597767680 total extent tree bytes: 102514688 btree space waste bytes: 325265468 file data blocks allocated: 6169163599872 referenced 575636733952 Could somebody please answer my initial questions about this obscure warning? Thanks, -- Tom Hale -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
check: "warning line 4144"
In running btrfs check, I got the following message: warning line 4144 Could this be a little more descriptive? * Does it mean I should rebuild my FS from scratch? * Is there anything I can do to remove this warning? Complete output below: == $ sudo btrfs check --repair -p /dev/mapper/fix-backup enabling repair mode Checking filesystem on /dev/mapper/fix-backup UUID: 0f5b7713-929d-41e7-b214-32500b5c77fc ref mismatch on [195215851520 16384] extent item 0, found 1 Backref 195215851520 parent 1463 root 1463 not found in extent tree backpointer mismatch on [195215851520 16384] owner ref check failed [195215851520 16384] repair deleting extent record: key 195215851520 169 1 adding new tree backref on start 195215851520 len 16384 parent 0 root 1463 Repaired extent references for 195215851520 Fixed 0 roots. cache and super generation don't match, space cache will be invalidated warning line 4144 [o] checking csums checking root refs found 294913892352 bytes used, no error found total csum bytes: 282955440 total tree bytes: 5166727168 total fs tree bytes: 4489232384 total extent tree bytes: 353075200 btree space waste bytes: 886405127 file data blocks allocated: 7930446508032 referenced 1126675288064 == -- Tom Hale -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: "Corrected" errors persist after scrubbing
nt/tmp # mdadm --stop /dev/md127 mdadm: stopped /dev/md127 # mdadm --stop /dev/md0 mdadm: stopped /dev/md0 # losetup -d /dev/loop[01] # -- Tom Hale May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 132972544 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 107016192 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 340852736 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 366804992 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 392626176 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 314896384 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 418050048 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 434962432 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 486998016 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 512688128 on dev /dev/md127 May 16 13:10:20 svelte kernel: BTRFS error (device md127): fixed up error at logical 132972544 on dev /dev/md127 May 16 13:10:20 svelte kernel: BTRFS error (device md127): fixed up error at logical 107016192 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 340852736 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 366804992 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 392626176 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 314896384 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 418050048 on dev /dev/md127 May 16 13:10:21 svelte kernel: BTRFS error (device md127): fixed up error at logical 434962432 on dev /dev/md127 May 16 13:10:22 svelte kernel: BTRFS error (device md127): fixed up error at logical 486998016 on dev /dev/md127 May 16 13:10:22 svelte kernel: BTRFS error (device md127): fixed up error at logical 512688128 on dev /dev/md127 May 16 13:04:30 svelte kernel: BTRFS info (device md127): disk space caching is enabled May 16 13:04:30 svelte kernel: BTRFS info (device md127): has skinny extents May 16 13:07:57 svelte kernel: BTRFS warning (device md127): i/o error at logical 132972544 on dev /dev/md127, sector 220800, root 5, inode 261, offset 305774592, length 4096, links 1 (path: rand) May 16 13:07:58 svelte kernel: BTRFS error (device md127): bdev /dev/md127 errs: wr 0, rd 1, flush 0, corrupt 0, gen 0 May 16 13:07:58 svelte kernel: BTRFS warning (device md127): i/o error at logical 107016192 on dev /dev/md127, sector 170104, root 5, inode 261, offset 278917120, length 4096, links 1 (path: rand) May 16 13:07:59 svelte kernel: BTRFS error (device md127): bdev /dev/md127 errs: wr 0, rd 2, flush 0, corrupt 0, gen 0 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 132972544 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 107016192 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS warning (device md127): i/o error at logical 340852736 on dev /dev/md127, sector 313984, root 5, inode 261, offset 196018176, length 4096, links 1 (path: rand) May 16 13:07:59 svelte kernel: BTRFS error (device md127): bdev /dev/md127 errs: wr 0, rd 3, flush 0, corrupt 0, gen 0 May 16 13:07:59 svelte kernel: BTRFS warning (device md127): i/o error at logical 366804992 on dev /dev/md127, sector 364672, root 5, inode 261, offset 221970432, length 4096, links 1 (path: rand) May 16 13:07:59 svelte kernel: BTRFS error (device md127): bdev /dev/md127 errs: wr 0, rd 4, flush 0, corrupt 0, gen 0 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 340852736 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS warning (device md127): i/o error at logical 392626176 on dev /dev/md127, sector 415104, root 5, inode 261, offset 247791616, length 4096, links 1 (path: rand) May 16 13:07:59 svelte kernel: BTRFS error (device md127): bdev /dev/md127 errs: wr 0, rd 5, flush 0, corrupt 0, gen 0 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 366804992 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS error (device md127): fixed up error at logical 392626176 on dev /dev/md127 May 16 13:07:59 svelte kernel: BTRFS warning (device md127): i/o error at logical 314896384 on dev /dev/md127, sector 263288, root 5, inode 261, offset 170061824, length 4096, links 1 (path: rand) May 16 13:07:59 svelte kernel: BTRFS error (de
"Corrected" errors persist after scrubbing
Below (and also attached because of formatting) is an example of `btrfs scrub` incorrectly reporting that errors have been corrected. In this example, /dev/md127 is the device created by running: mdadm --build /dev/md0 --level=faulty --raid-devices=1 /dev/loop0 The filesystem is RAID1. # mdadm --grow /dev/md0 --layout=rp400 layout for /dev/md0 set to 12803 # btrfs scrub start -Bd /mnt/tmp scrub device /dev/md127 (id 1) done scrub started at Fri May 5 19:23:54 2017 and finished after 00:00:01 total bytes scrubbed: 200.47MiB with 8 errors error details: read=8 corrected errors: 8, uncorrectable errors: 0, unverified errors: 248 scrub device /dev/loop1 (id 2) done scrub started at Fri May 5 19:23:54 2017 and finished after 00:00:01 total bytes scrubbed: 200.47MiB with 0 errors WARNING: errors detected during scrubbing, corrected # ### But the errors haven't really been corrected, they're still there: # mdadm --grow /dev/md0 --layout=clear # Stop producing additional errors layout for /dev/md0 set to 31 # btrfs scrub start -Bd /mnt/tmp scrub device /dev/md127 (id 1) done scrub started at Fri May 5 19:24:24 2017 and finished after 00:00:00 total bytes scrubbed: 200.47MiB with 8 errors error details: read=8 corrected errors: 8, uncorrectable errors: 0, unverified errors: 248 scrub device /dev/loop1 (id 2) done scrub started at Fri May 5 19:24:24 2017 and finished after 00:00:00 total bytes scrubbed: 200.47MiB with 0 errors WARNING: errors detected during scrubbing, corrected # Since scrub is checking for read issues, I expect that it would read any corrections before asserting that they have indeed been corrected. I understand that HDDs have a pool of non-LBA-addressable sectors set aside to mask bad physical sectors, but this pool size is fixed by the manufacturer (who makes money from sales of new drives). However, I don't believe it is sufficient to blindly trust that the underlying HDD still has spare reallocatable sectors or that the hardware will always correctly write data, given the verification and fixing intention of scrub. At a minimum, shouldn't these 8 "corrected errors" be listed as "uncorrectable errors" to inform the sysadmin that data integrity has degraded (e.g. in this RAID1 example the data is no longer duplicated)? Ideally, I would hope that the blocks with uncorrectable errors are marked as bad and fresh blocks are used to maintain integrity. -- Regards, Tom Hale # mdadm --grow /dev/md0 --layout=rp400 layout for /dev/md0 set to 12803 # btrfs scrub start -Bd /mnt/tmp scrub device /dev/md127 (id 1) done scrub started at Fri May 5 19:23:54 2017 and finished after 00:00:01 total bytes scrubbed: 200.47MiB with 8 errors error details: read=8 corrected errors: 8, uncorrectable errors: 0, unverified errors: 248 scrub device /dev/loop1 (id 2) done scrub started at Fri May 5 19:23:54 2017 and finished after 00:00:01 total bytes scrubbed: 200.47MiB with 0 errors WARNING: errors detected during scrubbing, corrected # ### But the errors haven't really been corrected, they're still there: # mdadm --grow /dev/md0 --layout=clear # Stop producing additional errors layout for /dev/md0 set to 31 # btrfs scrub start -Bd /mnt/tmp scrub device /dev/md127 (id 1) done scrub started at Fri May 5 19:24:24 2017 and finished after 00:00:00 total bytes scrubbed: 200.47MiB with 8 errors error details: read=8 corrected errors: 8, uncorrectable errors: 0, unverified errors: 248 scrub device /dev/loop1 (id 2) done scrub started at Fri May 5 19:24:24 2017 and finished after 00:00:00 total bytes scrubbed: 200.47MiB with 0 errors WARNING: errors detected during scrubbing, corrected #
