a day ago
- The author wanted to play Civilization 5 on Steam with a friend but uses a Linux/Windows dual-boot with a shared NTFS partition, requiring slow reboots due to disabled hibernate.
- Steam's compatibility layer (Proton) worked for single-player, but multiplayer had 'Could not connect to host' errors due to the firewall blocking random ports.
- The author normally uses an 'internet' group in IPTables to whitelist traffic per application, but applying it to Steam caused library mounting issues on the NTFS partition.
- The root cause was that Steam tried to create and run a shell script on the NTFS partition, but NTFS-3G set ownership to root:root for files written by other users/groups, breaking permissions.
- The solution was to explicitly add the 'internet' group to the UserMapping file in the NTFS mount point, resolving the permission conflicts and allowing everything to work.