Configuration Locations
aerynOS ships in a stateless layout, meaning the OS is completely separated from user data and configuration.
System defaults
Section titled “System defaults”The OS packages no longer reside under /etc. They now go to /usr/share/defaults. The traditional /etc directory hierarchy is preserved under /usr. /etc is now strictly reserved for User/Admin data and configuration. As a result all system updates now occur without touching user data.
| Purpose | Default location | Example contents |
|---|---|---|
| Base system settings | /usr/share/defaults/etc |
ld.so.conf, libnl, tpm2-tss |
| PAM policies | /usr/share/defaults/pam.d |
sudo, system-login, polkit-1 |
| Shell profiles | /usr/share/defaults/profile and /usr/share/defaults/profile.d |
00-aeryn.sh, interactive shell tweaks |
| Service defaults | /usr/share/defaults/environment.d |
Session-wide environment snippets |
| Sudo configuration | /usr/share/defaults/sudo |
sudoers, drop-in files |
| SSH defaults | /usr/share/defaults/ssh |
ssh_config, sshd_config |
Packages may add more directories under /usr/share/defaults as required, but the layout will always mirror where the file would have appeared under /etc on a traditional filesystem.
System overrides
Section titled “System overrides”Overrides are global (administrator-level) modifications that “override” the default environment of AerynOS, including system setup, configuration, hardware and current state. Because these overrides live in the /etc folder, they survive package updates. Create “drop-in” directories such as /etc/pam.d or /etc/sudoers.d to keep customisations scoped and easy to audit.
When you need to revert to the shipped defaults, remove the override from /etc and Moss will fall back to the matching file in /usr/share/defaults.
User-level configuration
Section titled “User-level configuration”User-level configurations include desktop and app settings. These follow the XDG Base Directory specification. Store per-user changes in:
~/.configfor configuration files~/.local/sharefor data files
System configuration lookups follow a strict path: The user’s personal configurations are prioritized. If any fail, the system falls back to the settings under /etc. If any of these in turn fail, it resolves to the system defaults at /usr/share/defaults.
Where to look next
Section titled “Where to look next”Run the following command to explore the current defaults on your system:
ls /usr/share/defaultsCombine this with moss search-file to identify which package owns a specific default file when you need to adjust or report an issue.