Technical overview

GNOME desktop

The GNOME configuration ships a stock gnome-shell with the following notable tweaks;

• Dark mode by default.
• A custom wallpaper.
• On first boot most core apps are installed as Flatpaks from Flathub.

Filesystem

The following changes are made to the filesystem to make it function in an immutable context.

These directories are linked to another location;

• /opt is symlinked to /var/opt.
• /srv is symlinked to /var/srv.
• /mnt is symlinked to /var/mnt.
• /usr/local is symlinked to /var/usrlocal.

These directories are subvolume which are mounted at boot using fstab, these volumes are shared between all deployments;

• /root is a subvolume located at /arkdep/shared/root.
• /home is a subvolume located at /arkdep/shared/home.
• /var/lib/flatpak is a subvolume located at /arkdep/shared/flatpak.

These directories are separate subvolumes which are subvolumes unique to each deployment;

• /etc is writable and unique to each deployment.
• /var is writable and unique to each deployment.

Operating system

The following changes are made to the operating system configuration to make it function in an immutable context.

• A patched version of the libnss-extrausers PAM module is included and enabled by default.
• shadow, passwd and group files with system accounts are stored in /usr/lib, these are loaded by the libnss-extrausers PAM module.