On 2017年12月12日 18:22, Juergen Sauer wrote: > Hi collegues, > this morning we've got a problm with btrfs in Debian Stable. > > Yesterday we had our fs filled below 30% space usage. > No further usage came in the usage is nearly the same, but ... > > # df -h . > Dateisystem Größe Benutzt Verf. Verw% Eingehängt auf > /dev/vdb1 483G 483G 148K 100% /mnt > > # btrfs fi df . > Data, single: total=480.97GiB, used=480.97GiB > System, single: total=32.00MiB, used=96.00KiB > Metadata, single: total=2.00GiB, used=1.29GiB > GlobalReserve, single: total=512.00MiB, used=0.00B > > # btrfs fi show . > Label: 'AXSDaten' uuid: fde7e31f-4127-4a9d-b7c6-774ceff8f7c1 > Total devices 1 FS bytes used 482.26GiB > devid 1 size 483.00GiB used 483.00GiB path /dev/vdb1 > > # btrfs --version > btrfs-progs v4.7.3 > > we found exerpt of kernel log: > [ 199.391577] attempt to access beyond end of device > [ 199.391598] vdb1: rw=536870984, want=1012922336, limit=1012922335
I doubt if it's just a off-by-one bug.
It can be that, btrfs think it's enlarged while partition table doesn't
think so, so btrfs tries to submit write beyond the partition end.
> [ 199.391615] BTRFS error (device vdb1): bdev /dev/vdb1 errs: wr 301,
> rd 0, flush 0, corrupt 0, gen 0
> r
> If I interpret the log right, on the FS the kernel wants to write on
> block 1012922336, but the fs was created with max 1012922335 blocks.
>
> Looks to us here like a typical off-by-one error on accessing the last
> block of device.
>
> This error was repeating under ff. conditions:
> - shutdown the virtual server (kvm),
> - extend the physical file of the according virtual hdd by 20% (from 483
> Gib to 520 GiB)
> - restart virtual server
> - fixed partion size (parted), mounted
> - called btrfs fi resize max on the corresponding mount point
The following info is needed to debug the problem.
1) Chunk tree dump of the btrfs:
# btrfs inspect dump-tree -t 3 /dev/vdb1
2) Super dump of the btrfs:
# btrfs inspect dump-super -f /dev/vdb1
3) Kernel version
# uname -a
(Well, I'm not a Debian user so I don't really know the kernel
version just by "Debian Stable")
4) Partition info
Better with binary output in byte unit.
Thanks,
Qu
>
> Error came back, nearly at once.
>
> Any other Idea to fix this error?
>
> mit freundlichen Grüßen
> Jürgen Sauer
>
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