Currently, macOS zabbix_agentd items vfs.fs.discovery and vfs.fs.get return very limited info about file systems, e.g.:
This is fine as long as you don't mount .dmg disk images. It's a standard way to install software on macOS.
Then the list looks like this:
If you're installing software and not unmounting the image right away, Zabbix filesystem discovery adds and monitors the mounted image as a normal file system and also generates problems about free disk space (since disk space is zero in such images).
This annoying behaviour can be addressed by adding a flag to the returned JSON. The flag can indicate whether the file system is a mounted disk image or a normal file system. Then the template can filter out such filesystems.