We haven't documented this properly yet, but the general advice is to:
- back up Postgres by making a database dump. See [Backing up PostgreSQL](maintenance-postgres.md#backing-up-postgresql)
- back up all `/matrix` files, except for `/matrix/postgres/data` (you already have a dump) and `/matrix/postgres/data-auto-upgrade-backup` (this directory may exist and contain your old data if you've [performed a major Postgres upgrade](maintenance-postgres.md#upgrading-postgresql)).
You can later restore these by:
- Restoring the `/matrix` directory and files on the new server manually
- Following the instruction described on [Installing a server into which you'll import old data](installing.md#installing-a-server-into-which-youll-import-old-data)
If your server's IP address has changed, you may need to [set up DNS](configuring-dns.md) again.
You can free some disk space from Docker by removing its unused data. See [docker system prune](https://docs.docker.com/engine/reference/commandline/system_prune/) for more information.
Docker containers that the playbook configures are supervised by [systemd](https://wiki.archlinux.org/title/Systemd) and their logs are configured to go to [systemd-journald](https://wiki.archlinux.org/title/Systemd/Journal).
Available service names can be seen by doing `ls /etc/systemd/system/matrix*.service` on the server. Some services also log to files in `/matrix/*/data/..`, but we're slowly moving away from that.
We just simply delegate logging to journald and it takes care of persistence and expiring old data.
The shortcut command with `just` program is also available: `just run-tags self-check`
If it's all green, everything is probably running correctly.
Besides this self-check, you can also check whether your server federates with the Matrix network by using the [Federation Tester](https://federationtester.matrix.org/) against your base domain (`example.com`), not the `matrix.example.com` subdomain.
SSL certificates are managed automatically by the [Traefik](https://doc.traefik.io/traefik/) reverse-proxy server.
If you're having trouble with SSL certificate renewal, check the Traefik logs (`journalctl -fu matrix-traefik`).
If you're [using your own webserver](configuring-playbook-own-webserver.md) instead of the integrated one (Traefik), you should investigate in another way.