Nagios Support Forum

I searched the forums and google and couldn't locate a similar problem. I have a RHEL5 system that I installed the Nagios Plugins on from EPEL, which contains version 1.4.15. On one of my file systems that isn't full, check_disk is reporting it as 100% full.

# df -h /data
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/rsig-rsig
120T 116T 4.7T 97% /data
# /usr/lib64/nagios/plugins/check_disk -V
check_disk v1.4.15 (nagios-plugins 1.4.15)
# /usr/lib64/nagios/plugins/check_disk -w 2 -c 1 -p /data
DISK CRITICAL - free space: /data 0 MB (0% inode=99%);| /data=121070864MB;125439998;125439999;0;125440000

I went ahead and downloaded the latest nagios-plugins tar package from the web site and compled from source, and it gives the same problem:

# /root/nagios-plugins-2.0.3/plugins/check_disk -V
check_disk v2.0.3 (nagios-plugins 2.0.3)
# /root/nagios-plugins-2.0.3/plugins/check_disk -w 2 -c 1 -p /data
DISK CRITICAL - free space: /data 0 MB (0% inode=99%);| /data=121070864MB;125439998;125439999;0;125440000

Both check_disk versions work fine on other file systems:

# df -h /work
Filesystem Size Used Avail Use% Mounted on
/dev/workfs 626T 535T 92T 86% /work
# /usr/lib64/nagios/plugins/check_disk -w 2 -c 1 -p /work
DISK OK - free space: /work 95478888 MB (14% inode=71%);| /work=560603184MB;656082070;656082071;0;656082072


The underlying file system that I am having problems with (/data) is an XFS formated file system. The device is a LVM2 device containing multiple, multipath LUNs:

# pvscan
PV /dev/mpath/360a9800064665861483465564f444c79 VG rsig lvm2 [10.81 TB / 669.61 GB free]
PV /dev/mpath/360a98000646e6c51566f655745313958 VG rsig lvm2 [10.16 TB / 876.00 MB free]
PV /dev/mpath/360a98000646658614834655743595739 VG rsig lvm2 [10.81 TB / 669.61 GB free]
PV /dev/mpath/360a98000646e6c51566f655747363374 VG rsig lvm2 [10.81 TB / 669.61 GB free]
PV /dev/mpath/360a980006466586148346557452d6a77 VG rsig lvm2 [10.16 TB / 620.00 MB free]
PV /dev/mpath/360a98000646e6c51566f655747356939 VG rsig lvm2 [10.81 TB / 669.61 GB free]
PV /dev/mpath/360a980006466586148346557452d5273 VG rsig lvm2 [10.16 TB / 620.00 MB free]
PV /dev/mpath/360a98000646e6c51566f655745326f7a VG rsig lvm2 [10.16 TB / 876.00 MB free]
PV /dev/mpath/360a980006466586148347047354e6339 VG rsig lvm2 [15.91 TB / 5.64 GB free]
PV /dev/mpath/360a98000646658614834704739354966 VG rsig lvm2 [15.91 TB / 536.00 MB free]
PV /dev/mpath/360a98000646658614834704739374735 VG rsig lvm2 [7.04 TB / 6.77 GB free]

# lvdisplay /dev/mapper/rsig-rsig
--- Logical volume ---
LV Name /dev/rsig/rsig
VG Name rsig
LV UUID 6I9rxz-8Qcb-cmvJ-x9Py-DvN8-fwAp-yjEnfc
LV Write Access read/write
LV Status available
# open 1
LV Size 120.09 TB
Current LE 31480364
Segments 4
Allocation inherit
Read ahead sectors auto
- currently set to 2048
Block device 253:15

Are there any known issues with check_disk and XFS or LVM2 with multiple physical volumes? Thanks.

First, when trying to debug stuff like this, df -h output can lead to rounding errors. df -k and df -i (for inode usage) is better (if harder to wrap your head around the numbers).

Second, I'm guessing with your 120T disk, you're blowing the limits on the counters inside check_disk.c. The last note in the NEWS file for the plugins was from 1.4.12 on 27 May 2008:

check_disk should now work with large file systems (2TB+) on all archs that supports it

That's six years ago, and LOTS has changed in file system sizes since then. I'm guessing Spencer may chip in here...

I'm honestly not sure what the int size is for check_disk, hoping its a 64 bit unsigned int, but my initial guess would be that over 100tb overflows it when converted to MB. I will have a look at the code and can see what we can do. It clearly seems to be picking it up for perfdata, just something with the display in normal status output and in use for threshold checks. Should be pretty easy to track down, I'll work on that this weekend or on my flight Friday.

Edit: Can you do me a huge favor and submit a bug on github.com/nagios-plugins/nagios-plugins? With all of your details and a link back here please. That way I can assign it to myself and have a reminder.