The Linux filesystem module monitors "Used Space" and "Total Space" and "Percent Used"

In"Total Space", the reserved space is included. However it is NOT included in "Used Space". For large filesystems, there can be larger than 5GB reserved space. So the trigger never works.

The critical disk space warning note says:

 Second condition should be one of the following:
 - The disk free space is less than 5G.
 - The disk will be full in less than 24 hours.

The trigger expression:

{Template Module Linux filesystems by Zabbix agent:vfs.fs.size[{#FSNAME},pused].last()}>{$VFS.FS.PUSED.MAX.CRIT:"{#FSNAME}"} and
(({Template Module Linux filesystems by Zabbix agent:vfs.fs.size[{#FSNAME},total].last()}-{Template Module Linux filesystems by Zabbix agent:vfs.fs.size[{#FSNAME},used].last()})<5G or {Template Module Linux filesystems by Zabbix agent:vfs.fs.size[{#FSNAME},pused].timeleft(1h,,100)}<1d)

The description says "disk free space is less than". However, the trigger expression uses "total - used" which is not same as  "free space". Because it does NOT take reserved space into consideration.

This is a serious bug as we had several cases where the trigger was never triggered. Suggestion is to monitor the Free Space and use Free Space < 5G in the trigger directly instead of calculating free space from other values.

Thanks,