mount.steamos

Mount all necessary partitions from a device to a target directory

$ sudo mount.steamos [/dev/sdX] [/mnt]

$ sudo mount.steamos -o nohome,nooverlay [/dev/sdX] [/mnt]

$ sudo mount.steamos -u [/mnt]

$ mount.steamos -h

mount.steamos [options] device mountpoint

mount.steamos mounts or unmounts SteamOS filesystem partitions, used primarily for accessing Steam Deck storage when booted from another operating system or recovery media.
SteamOS uses a complex partition layout with multiple overlays for system updates and user data separation. This tool handles the specific mount requirements, including the A/B root partitions, overlay filesystems, and home directory.
The command simplifies what would otherwise require multiple mount commands with specific options for each partition.

-o, --options _opts_

Mount options (nohome, nooverlay, etc.)

Unmount all partitions under the specified directory

Display help information

Requires root privileges. Designed specifically for SteamOS partition layouts (Steam Deck). The device should be a complete disk device (e.g., /dev/sda), not individual partitions. Ensure SteamOS is not running when mounting its partitions from another system.

mount(8), steamos-dump-info(1), umount(8)