First sorry, this is my first bug report in this project, please help clasify it correctly. Just ask for more info and I will try to give it. Furthermore please baer with me, it might be my misconfiguration that leads to this error.

Steps to reproduce:

1. Create new item under a host
2. change Name
3. Make sure that there is a folder on client server that is called /tmp and there is a somelog.log in the folder
4. set key to vfs.dir.size[/tmp,log] as descriped in documentation https://www.zabbix.com/documentation/3.4/manual/config/items/itemtypes/zabbix_agent
5. wait until data should be collected

Result:
First when the item is created at ones, then the status is enabled. Then afterwards under item status there is stated "Not supported" and under info, there is a red "i" with hover text: unsupported item key.
Sure no data gets through to zabbix.

Expected:

1. If there is an example in the documentation, that example should at least work...
2. There should be more information shown the user
3. Zabbix should return the size of the folder descriped