[Pkg-nagios-devel] Bug#800345: Bug#800345: check_disk sees wrong disk consumption on btrfs

[Klaus Ethgen]

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Hi,

Am Mo den 28. Sep 2015 um 10:17 schrieb Jan Wagner:
> Am 28.09.15 um 09:46 schrieb Klaus Ethgen:
> > Since several days, one of my checks went red for one of my boxes, 
> > mentioned that / is 100% full. But this is not true, there is
> > plenty of space left.
> > 
> > ~> df -Th Filesystem               Type      Size  Used Avail Use%
> > Mounted on /dev/sda1                btrfs     502M  338M  169M  67%
> > / ...
> > 
> > ~> btrfs fi df / System, single: total=4.00MiB, used=4.00KiB 
> > Data+Metadata, single: total=497.81MiB, used=329.71MiB 
> > GlobalReserve, single: total=8.00MiB, used=0.00B
> 
> I neither use btrfs nor do I have specific knowledge about this FS.

Well, for the tools it should just look as any other filesystems.

> > ~> /usr/lib/nagios/plugins/check_disk -w '3%' -c '1%' DISK CRITICAL
> > - free space: / 0 MB (0% inode=-)]; ...
[...]
> I think you can get a bit more information about what happens behind
> the scenes when running /usr/lib/nagios/plugins/check_disk -vvv

   ~> /usr/lib/nagios/plugins/check_disk -w '3%' -c '1%' -vvv
   Thresholds(pct) for / warn: 3,000000 crit 1,000000
   calling stat on /
   For /, used_pct=100 free_pct=0 used_units=337 free_units=0 total_units=501 used_inodes_pct=-1 free_inodes_pct=101 fsp.fsu_blocksize=4096 mult=1048576
   Freespace_units result=0
   Freespace% result=2
   Usedspace_units result=0
   Usedspace_percent result=0
   Usedinodes_percent result=0
   Freeinodes_percent result=0

And to give you what stat gives:
   ~> stat -f /
     File: "/"
       ID: a446833a80ceeb6a Namelen: 255     Type: btrfs
   Block size: 4096       Fundamental block size: 4096
   Blocks: Total: 128472     Free: 42014      Available: 43031
   Inodes: Total: 0          Free: 0

> Maybe this can help understanding where it might fail.

I don't see any that helps. I do not see where check_disk gets thevalues
from. But it just doesn't match the real values.

> GIT d-- s+: a C+++ UL++++ P+ L+++ E--- W+++ N+++ o++ K++ w--- O M V- PS
GCS/GIT d-- s+:- a+ C++ U(L/A/S)++++ P++++ L+++ E--- W- N+++ o+ K- w-- O++ M-- V- PS+++

> PE Y++
PE-- Y+

> PGP++ t-- 5 X R tv- b+ DI D+ G++ e++ h---- r+++ y++++
PGP++ t++ 5 X- R+ !tv b++ DI+ D+ G e+++ h+ r y?

Regards
   Klaus
- -- 
Klaus Ethgen                              http://www.ethgen.ch/
pub  4096R/4E20AF1C 2011-05-16   Klaus Ethgen <Klaus at Ethgen.de>
Fingerprint: 85D4 CA42 952C 949B 1753  62B3 79D0 B06F 4E20 AF1C
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