[Xymon] Xymon client on MacOS Catalina (10.15)

Brian Scott Brian.Scott at bunyatech.com.au
Sat Sep 5 05:29:54 CEST 2020

Hi list,

Has anyone had experience with running the xymon client on the latest Macos?

My particular problem is that the handling of disk mounts and capacities
has gone seriously weird. First exhibit - output from the mount command:

# mount
/dev/disk1s1 on / (apfs, local, read-only, journaled)
devfs on /dev (devfs, local, nobrowse)
/dev/disk1s2 on /System/Volumes/Data (apfs, local, journaled, nobrowse)
/dev/disk1s5 on /private/var/vm (apfs, local, journaled, nobrowse)
map auto_home on /System/Volumes/Data/home (autofs, automounted, nobrowse)

All volumes are either marked nobrowse or read-only so no disks are
selected by xymonclient-darwin.sh. This has the immediate kick on effect
of causing a bash set command to dump all set variables because the
filesystem list is empty. Ignoring this because we actually want to
select some filesystems, the question is which ones. Looking at the
output from df:

# df -P -H
Filesystem      Size   Used  Avail Capacity  Mounted on
/dev/disk1s1    1.0T    11G    92G    11%    /
devfs           345k   345k     0B   100%    /dev
/dev/disk1s2    1.0T   893G    92G    91%    /System/Volumes/Data
/dev/disk1s5    1.0T   3.2G    92G     4%    /private/var/vm
map auto_home     0B     0B     0B   100%    /System/Volumes/Data/home

It looks like /dev/disk1s1, s2 and s5 are all the same real partition
but account for different space from it, i.e. total size = 1.0T, Used =
11G+893G+3.2G=907.2G, Avail=92G.

This would suggest that a reasonable thing to monitor would be one of
these entries ('/' makes some sense) and derive used as size-avail

This then falls down when I plug an extra disk in (in this case a FAT32
USB drive) adding:

/dev/disk2s1 on /Volumes/NO NAME (msdos, local, nodev, nosuid, noowners)


/dev/disk2s1     15G   137M    15G     1%    /Volumes/NO NAME

Which looks a lot more like conventional drives on a normal unix-style

Fortunately (?) for me, the server I'm trying to monitor only has a
single disk so this isn't a further complicating issue.

Has anyone already done anything to make sense of all this in a modified
version of xymonclient-darwin.sh? Is there a cutoff point in macos
versions where the existing script was good and a new one is needed? I
haven't had to deal with a Mac server before so haven't particularly
cared about what xymon made of it until now.

Cheers, stay safe,

Brian Scott

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