A quick reference for Debian 13 “trixie”: updates, package sources, the firewall, networking, /tmp in memory and support dates.
Our images use Debian 13 “trixie”. Updates are released until August 2028, and long-term support (LTS) continues until June 2030. Log in as debian and run administrator commands with sudo.
Updating
sudo apt update
sudo apt upgradesudo apt full-upgrade also updates anything that requires packages to be removed or replaced. You need to reboot after a kernel update. Before a major upgrade, take a server snapshot.
Security updates are installed automatically: the image has unattended-upgrades enabled. To configure or turn it off, run sudo dpkg-reconfigure unattended-upgrades.
Package sources
Debian 13 describes its package sources in the new format, in /etc/apt/sources.list.d/debian.sources. In our image the mirror address is kept separately, in /etc/apt/mirrors/debian.list. You can convert an old sources.list to the new format with sudo apt modernize-sources.
Software and services
sudo apt install nginx | install |
sudo apt remove nginx | remove; purge also removes the configuration |
apt search keyword | find a package |
systemctl status nginx, journalctl -u nginx | the state and log of a service |
For other common commands, see Essential Linux commands.
Firewall
The image doesn’t come with a firewall enabled. The simplest option is to install ufw — and allow SSH before you turn it on:
sudo apt install ufw
sudo ufw allow 22/tcp
sudo ufw allow 80,443/tcp
sudo ufw enableIf you lose access, log in through the console in your control panel and run sudo ufw disable.
To open other ports, and for what to do if a port doesn’t respond, see How to open a port on your server.
Networking
The network is configured through netplan when the server is created, in /etc/netplan/50-cloud-init.yaml. To check it, use ip -4 addr and ip route; for DNS servers, use resolvectl status. Apply changes with sudo netplan try: if something goes wrong, the previous settings are restored automatically.
Things worth knowing
- /tmp is stored in RAM (up to half of it) and is emptied on reboot. Files older than 10 days in
/tmpand older than 30 days in/var/tmpare deleted automatically. Don’t keep anything important there. - DSA SSH keys are no longer supported — use ed25519.
- Time is synchronised by systemd-timesyncd: check it with
timedatectl.
To see the version of the system, run cat /etc/debian_version.
Didn’t find the answer? Ask our support team — we’ll help.