Valheim Dedicated Server Setup (Debian 13)

One-command interactive setup for a Valheim dedicated server on a fresh Debian 13 install, using SteamCMD and a systemd service.

Requirements

• Debian 13 (should work on 12 too)
• x86_64 architecture only (ARM/aarch64 is not supported — the Valheim dedicated server binary won't run on it)
• Root access (sudo)
• ~4 GB RAM (8 GB recommended), ~20 GB disk
• UDP ports 2456-2458 open (adjust to your chosen port)
• If deploying inside a container (LXC, Docker) behind NAT, you'll also need port forwarding configured at the host level — see Troubleshooting.

Install

git clone https://github.com/stealthyjs/valheim-server.git
cd valheim-server
chmod +x install.sh
sudo ./install.sh

The installer will prompt for server name, world name, password, port, public listing and backup retention, then install everything.

Note: the server password must be at least 5 characters and cannot be contained in the server name.

Manage

Action	Command
Start	sudo systemctl start valheim
Stop	sudo systemctl stop valheim
Status	systemctl status valheim
Logs (service)	journalctl -u valheim -f
Logs (game server)	tail -f /opt/valheim/logs/valheim-$(date +%F).log
Update	sudo /opt/valheim/update.sh

Updates

Valheim frequently releases patches that require updating the dedicated server (otherwise players with updated clients won't be able to connect).

To update the server to the latest version via SteamCMD:

sudo /opt/valheim/update.sh

(This script will fetch the latest update and automatically restart the systemd service).

Backups

A nightly cron job (4 AM) backs up worlds to /opt/valheim/backups.

Troubleshooting

Service fails with exit code 127 The launch script's shebang may have Windows-style line endings (CRLF). Fix with:

sudo dos2unix /opt/valheim/start_valheim.sh

Service starts then exits quickly (status 0, no obvious error) Check the game server's own log, not journalctl — the launch script redirects all output there:

tail -100 /opt/valheim/logs/valheim-$(date +%F).log

Look for steamclient.so: cannot open shared object file. If present, Steamworks can't find its SDK library. Fix with:

mkdir -p /home/valheim/.steam/sdk64
ln -sf /opt/valheim/linux64/steamclient.so /home/valheim/.steam/sdk64/steamclient.so
chown -h valheim:valheim /home/valheim/.steam/sdk64/steamclient.so
sudo systemctl restart valheim

valheim_server.x86_64: No such file or directory after install reports success SteamCMD can return a success exit code even when the download didn't fully land in /opt/valheim — commonly a permissions issue. Fix and retry:

sudo chown -R valheim:valheim /opt/valheim
sudo -u valheim /opt/steamcmd/steamcmd.sh +force_install_dir /opt/valheim \
  +login anonymous +app_update 896660 validate +quit

Client shows "Incompatible version" when connecting The dedicated server is behind the Steam client build. Force an update:

sudo systemctl stop valheim
sudo /opt/valheim/update.sh
sudo systemctl start valheim

Client hangs on "Connecting..." then times out Usually a network/firewall issue, not a server problem:

• Confirm the server is actually listening: sudo ss -ulnp | grep 2456
• If running in a container behind NAT (LXC on Proxmox, Docker bridge, etc.), confirm the host has a DNAT/port-forward rule sending UDP 2456-2458 to the container's private IP — this must be configured on the host, not inside the container, and is easy to lose after a host reboot if it wasn't made persistent.

Uninstall

sudo ./uninstall.sh