ferment9348/valheim repository overview

⁠Valheim — dedicated server

Valheim dedicated server, built for Unraid but an ordinary Docker image that runs anywhere. The game ships a native Linux server binary, so SteamCMD installs it and it runs directly — no Proton, no wine, no virtual display.

First boot downloads about 2GB and settles at about 2.1GB. A new world generates in well under a minute.

There is no config file: every setting is a launch flag, so changing one and restarting takes effect immediately and nothing you edit by hand is overwritten.

• Guide: https://github.com/blckassassin/unraid-game-servers/blob/main/games/valheim/README.md⁠
• Source: https://github.com/blckassassin/unraid-game-servers⁠
• Issues: https://github.com/blckassassin/unraid-game-servers/issues⁠

⁠Run it

docker run -d --name valheim \
  -p 2456:2456/udp -p 2457:2457/udp -p 2458:2458/udp \
  -e SERVER_NAME="My Server" \
  -e WORLD_NAME="Dedicated" \
  -e SRV_PWD="atleast5chars" \
  -e UID=99 -e GID=100 \
  --stop-timeout 150 \
  -v /mnt/user/appdata/valheim:/serverdata/serverfiles \
  -v /mnt/user/appdata/steamcmd:/serverdata/steamcmd \
  ferment9348/valheim:latest

--stop-timeout 150 is not optional. See Stopping safely below.

⁠The password rules

Three, all enforced by the server by refusing to start. This image checks them first so the log tells you which one you broke.

1. At least 5 characters.
2. The password must not appear anywhere inside the server name. A server called Jordan's Valheim with password valheim will not start.
3. A server with PUBLIC=1 must have one. For no password, set PUBLIC=0.

⁠Ports

Steam's View → Servers → Favourites → Add a server box wants the query port, 2457, not the game port. That catches nearly everyone once.

Read out of a running container: with crossplay off the server binds 2456 and 2457; with crossplay on it binds 2457 only. 2458 was never seen bound in either mode — it is published to match the advice in the server's own start script.

To move the port, set the host port, the container port and GAME_PORT all to the same number, with the query port following at plus one. On Unraid the container port box is greyed out for any port a template supplied, so remove the Game Port row and add your own — an entry you create yourself has no container port yet, so Unraid leaves it editable.

⁠Common settings

A misspelled preset, modifier or toggle stops the container with a message listing the valid values, because the server's own response to one is to ignore it silently and hand you a normal world.

⁠Crossplay

CROSSPLAY=true moves the server to the PlayFab backend. Console players can then join, and no port forwarding is needed because traffic is relayed. In exchange the server is listed in the in-game Community servers list and not in the Steam server browser — expected, not a fault — and BepInEx mods are reported not to load.

⁠Where your world lives

Everything persistent is under one directory, savedir, inside the game files volume: worlds_local/<World Name>/ plus adminlist.txt, bannedlist.txt and permittedlist.txt.

Two things worth knowing. Worlds go in worlds_local/, never worlds/ — the server does not read the latter and will quietly generate a new world instead of telling you. And an admin ID is the Platform User ID copied verbatim from the in-game F2 panel or the server log, case sensitive; a bare SteamID64 is accepted into the file and then silently ignored, with no error anywhere.

⁠Stopping safely

The shutdown save is the only save this container can ask for — Valheim has no RCON, no console and no remote save command, so there is no fallback if the stop is cut short.

Measured: a stop took 4.2 seconds on a freshly generated world and wrote it correctly. A real world takes longer and keeps growing, which is why STOP_TIMEOUT defaults to 120.

Docker's default stop grace is 10 seconds, which would kill the server partway through that save. Pass --stop-timeout 150, or on Unraid raise the container stop timeout to at least 150 — there it is a single global setting, so check it after an Unraid update.

⁠Memory

About 3GB idle, 6–8GB for a busy long-running world; 1.4GB was resident right after generating a world with nobody connected. Memory use grows over time, a long-reported trait of this server, so a scheduled nightly restart is worth setting up. That is safe, because the stop saves.

⁠Volumes

⁠Source and support

Built from https://github.com/blckassassin/unraid-game-servers⁠ — issues and questions there. MIT licensed.