Disk and persistence¶
gewis.tmpfsRoot lays the disk out: / is a 2 GiB tmpfs, wiped every boot,
and the NVMe carries an ESP plus a btrfs partition with /nix and /persist
subvolumes, both compress=zstd,noatime.
What survives a reboot is whatever the enabled modules put on /persist:
| Path | Kept by |
|---|---|
/var/lib/nixos, /var/lib/systemd, /var/log/journal, /etc/machine-id |
gewis.persistence |
/var/lib/comin |
gewis.comin |
/var/lib/netbird |
gewis.netbird |
/var/lib/service-pc |
gewis.servicePc.remote, the RDP certificate |
/etc/ssh/ssh_host_ed25519_key and its .pub |
gewis.admin |
A file that is not on that list does not exist after the next boot. A host
adds its own through gewis.persistence.extraDirectories and extraFiles.
The sops age key lives at /persist/var/lib/sops-nix/key.txt, outside the
tmpfs, so secrets decrypt on boot.