On 2016-05-05 14:22, Stephen Berg (Contractor) wrote:
> Had this problem for quite awhile now, still haven't found a solution.
> 
> We use NFS automounts quite extensively here.  Lot's of filesystems that show up (to the user's) as /u/<blah>.  On the system where the filesystem actually lives it will be available as /u/<blah> and also /export/<blah>.  If the /u/<blah> mount point is mounted on a system where it's hosted df doesn't show the /export/<blah> mount point and the check_mk service to monitor that filesystem goes into an UNKN state.
> 
> I think it's because the agent see the bind mount and ignores the actual mount point in it's df output.
> 
> If I look in /proc/mounts I see:
> 
> /dev/mapper/732254-common mounted on /export/new_common
> 
> and
> 
> /dev/mapper/732254-common mounted on /common
> 
> That's what I expect to see, but running df I only see the filesystem mounted on /common.  That's where check_mk gets messed up since it inventoried the filesystem as being on /export/new_common.
> 
> Is there anyway to get df to ignore automounted mount points and only show the actual mount point?  I've looked through the man page and can't find any option to get that to happen.
> 
> 

Long time ago since I played with check_mk, but I remember the agent was a simple shell script.

looking up the agent code in the check_mk git ...
http://git.mathias-kettner.de/git/?p=check_mk.git;a=blob_plain;f=agents/check_mk_agent.linux;hb=refs/heads/master

echo '<<<df>>>'
# The exclusion list is getting a bit of a problem. -l should hide any remote FS but seems
# to be all but working.
excludefs="-x smbfs -x cifs -x iso9660 -x udf -x nfsv4 -x nfs -x mvfs -x zfs -x prl_fs"
...

There a is a special handling for the nfs mounts, where you can try to fix / change the reporting

# Check NFS mounts by accessing them with stat -f (System
# call statfs()). If this lasts more then 2 seconds we
# consider it as hanging. We need waitmax.
if type waitmax >/dev/null
...

-- 
HTH,
olli