Monitoring a Mount Point with Zabbix

A subtle issue I ran into was the issue that Proxmox VE would sometimes unmount a GlusterFS volume and would fail to backup.  This issue was a bit sneaky though, since the PVE backup program wouldn’t execute it wouldn’t send an email notifying me of the failure.  This would make it so the backups would fail silently for some time, until I happened to login and see the errors in the cluster’s log.