First make sure that /mnt/videovalvonta directory already exists. Then just try the command w/o using HA. I used HA Supervised so I usually just pop open the shell of the homeassistant docker container from Portainer and try my commands that way.
This hack that you quoted works for me in HassIO — I’m not sure how different HassOS is and whether it can accept that ONLY workaround I’ve found.
As an FYI, after I upgrade HassIO, HA comes up in safe-mode because the folder /mnt/mystuff does not exist so the mount command fails. I used Node-RED single click automation that runs a docker exec command to create that folder in the homeassistant container, then restarts the container. This brings everything back to normal — but again it’s only after an upgrade. I’m happy to share that Node-RED flow if somebody is interested but it’s pretty simple. They key is in the fact that my Node-RED is hosted on the Ubuntu host and NOT by HassIO. This is key in having Node-RED with admin privileges and ability to control docker containers with shell commands.
Just as an FYI, I did allow guest to have FULL ACCESS to that folder. That basically cuts out the user authentication piece. I’m on a QNAP NAS which is sharing this folder NFS.
I have the same problem (and based on the folder name, looks like the same use case also ). Can’t get it to work. Tried setting chmod 777 on the folder on both computers, if that’s what you meant.