[SOLVED] adding an externally mounted drive to flatpak installed steam on debian base linux (Pop!_OS)

[Plastic Straw]

I've been struggling for a while to find a way to add my NTFS formatted drives to Steam on Linux. I did a fresh install of Pop!_OS and unbeknownst to me at the time I installed the Flatpak version of Steam so it was sandboxed.

If you have installed steam with Flatpak this solution should work for you on Debian based distros.

The solution to add drives is as follows:

1. Make sure you have your drives mounted properly (Guide here: https://www.liberiangeek.net/2012/04/auto-mount-windows-ntfs-partitions-in-ubuntu-12-04-precise-pangolin/)

2. Allow Steam sandbox to reach the external drive (flatpak override --user --filesystem=/path/to/mounted/drive com.valvesoftware.Steam)

for example my driver were under /media/veracryptX so the "--filesystem=/path/to/mounted/drive" part would look like this:

"--filesystem=/media/veracrypt3/SteamLibrary"

3. Restart steam (top right button labelled "steam" then press exit.) Open steam again and add drives like normal.

I hope this helps someone. I know I could have used a guide on this myself. Let me know if I need to add anything.

Cheers!

[Der tüddelige Fußgänger]

Also if you want to use flatpakas your primary package format. I stall an app called "flatseal" (flatpak install flatseal)
It lets you control permissions with an easy to use gui

[Panos21sonic]

Im getting:
Couldn't write /etc/machine-id/.steam_exec_test.sh: Not a directory
Couldn't write /etc/ld.so.conf/.steam_exec_test.sh: Not a directory
Couldn't write /usr/share/zoneinfo/.steam_exec_test.sh: Read-only file system
Couldn't write /media/panos/wd1tb/.steam_exec_test.sh: Permission denied
Couldn't write /run/host/os-release/.steam_exec_test.sh: Not a directory
Couldn't write /tmp/.X11-unix/X0/.steam_exec_test.sh: Not a directory
Couldn't write /run/host/fonts/.steam_exec_test.sh: Read-only file system

My drive is mounted at /media/panos/wd1tb

[funeraldoom]

2. Worked for me. Thanks.

[Ben Dover]

Solved my steam's disk write error, thanks a lot!

[D. Flame]

Yeah, flatseal is the way to go.

[ZzZzZzZzZz]

This worked for me as well. Fedora 40. steam flatpak. ty

[breneka]

This worked so fine! Thank you very much!

[itsfood]

Flatseal is a lifesaver, I had no idea I could manage perms like I could a docker container. It is perfect, thank you so much. Added my drive with rw perms and it found it and started installing immediately.