Games Valheim

Valheim server requirements

Build 25527701, 2026-10-05. Native Linux server. Steam SteamDB

Valheim dedicated server

Idle memory	1.3 GB
Peak memory	1.8 GB
CPU, idle	14% of one core
Ready after	41 s
Install size	2.1 GB
World save	144 KB
Ports	UDP 2456, 2457
Max players	10
Server app	896660
Build	25527701
Measured	2026-10-05
Raw data	CSV, 857 samples

Requirements

	Our benchmark	Iron Gate	LinuxBuz	Pine Hosting
CPU	14% of one core, idle		2 to 4 modern cores, per-core speed first	Quad-core, about 3 GHz+
RAM	1.3 GB idle, 1.8 GB peak		4 GB small, 4 to 6 GB for 5 to 10, 8 GB modded	4 GB+ server, 8 GB system min, 16 GB+ rec
Disk	2.1 GB install		SSD, 10 to 20 GB basic, 30 to 60 GB modded	SSD or NVMe
Network	UDP 2456 and 2457	Ports 2456-2457, no forwarding with crossplay	10 Mbps upload, 20+ Mbps near 10 players, ports 2456-2457	Broadband, good upload
OS	Linux, native	Windows or Linux, glibc 2.29+	Windows or Linux	64-bit Windows

RAM by players

1 to 45 to 89 to 10

Modded server

LinuxBuz

4 GB

Pine Hosting

4 GB

Recommended

LinuxBuz: "Four gigabytes of available RAM is a sensible starting point for a small vanilla server."
Pine Hosting: "1-4 players, vanilla: 4GB. 4-8 players, established world or light mods: 6GB. 6-10 players, larger worlds or heavier mods: 8GB+."

Memory over time

In use
Peak, with cache

Raw data (CSV)

Pending

24 hours idle
One player for 30 minutes
Three warm restarts

Ports

Port	Protocol	Use	Our server
`2456`	UDP	Game traffic. The `-port` value.	Open
`2457`	UDP	The `-port` value plus one. Forward it too.	Open

Forward both UDP ports. With -crossplay: PlayFab relay, no forwarding.

Docker setup

4 steps

Download

Free anonymous download, Steam app 896660. +app_info_update 1 avoids a first-run SteamCMD 'Missing configuration' error.

docker run --rm -v /srv/games/valheim:/data steamcmd/steamcmd:latest \
  +@sSteamCmdForcePlatformType linux +force_install_dir /data \
  +login anonymous +app_info_update 1 +app_update 896660 validate +quit

Image
Iron Gate's Dockerfile, in the download's docker folder. Installs the manual's three libraries.
```
cd /srv/games/valheim
docker build -t valheim_server docker
```

Run

Exact bench command, minus the password. Add -p 2456-2457:2456-2457/udp to publish the ports; -crossplay for console and Game Pass players.

docker run -d --name valheim \
  -v valheim_save:/root/.config/unity3d/IronGate/Valheim \
  -v /srv/games/valheim:/irongate -w /irongate \
  -e SteamAppId=892970 -e LD_LIBRARY_PATH=/irongate/linux64 \
  valheim_server ./valheim_server.x86_64 -nographics -batchmode \
  -name "My server" -port 2456 -world "Dedicated" -password "change-me" -public 1

Ready line
Iron Gate's manual: ready at 'Game server connected'. Fresh world: 'Loading: Done' 41 seconds after container start.
```
docker logs -f valheim | grep -E "Game server connected|Loading: Done"
```

Settings

16 settings

Flags on the start command.

Setting	What it does
`-name "My server"`	Name in the server list. Must not contain the password.
`-port 2456`	First of two ports; the second is this plus one.
`-world "Dedicated"`	World to load, or create if missing.
`-password "secret"`	At least 5 characters. Not in the server name.
`-public 1`	1 listed (default). 0 hidden; players use Join IP.
`-savedir PATH`	Worlds plus admin, banned and permitted lists. Linux default: ~/.config/unity3d/IronGate/Valheim
`-saveinterval 1800`	Seconds between world saves. Default 1800 (30 minutes).
`-backups 4`	Automatic backups to keep. Default: one 2 hours old, three 12 hours apart.
`-backupshort 7200`	Seconds to the first automatic backup. Default 7200 (2 hours).
`-backuplong 43200`	Seconds between later backups. Default 43200 (12 hours).
`-crossplay`	PlayFab backend; any platform can join. Without it, Steam only.
`-instanceid "1"`	Unique value per server, for several on one port and machine.
`-preset hard`	World modifier preset: Normal, Casual, Easy, Hard, Hardcore, Immersive or Hammer. Overrides earlier modifiers.
`-modifier raids none`	One world modifier, such as combat, deathpenalty, resources, raids or portals. Goes after `-preset`.
`-setkey nomap`	World modifier checkbox: nobuildcost, playerevents, passivemobs or nomap.
`-logFile PATH`	Server log to a file.

Troubleshooting

7 problems

Server missing from the list: -public 0 hides it; players use Join IP. With -public 1, allow a few minutes for the list to update.
Nobody can join after a permittedlist.txt edit: Any entry bans everyone not on the list (Iron Gate's manual). Add every player's ID, or empty the file.
No connections from outside the network: Forward UDP -port and the next port (2456 and 2457 by default). Or -crossplay: PlayFab relay, no forwarding.
Crossplay server unreachable by local IP: Expected; crossplay goes through the relay. Use the public IP and port, the join code or the server list.
Server fails to start on older Linux: Needs GLIBC 2.29 and GLIBCXX 3.4.26 or newer. Iron Gate suggests Docker, as above.
World stops saving: No save below about 204 MB free disk; warning below about 408 MB. Both limits logged at every save. Free space on the save folder's disk.
World or progress lost after a crash: Stop with Ctrl+C so it saves. Automatic backups sit beside the world files in the save folder.

Method

build 25527701

Server	Valheim dedicated server, Steam build 25527701, downloaded 2026-10-05.
Image	Iron Gate's official Dockerfile (Ubuntu 22.04 with libatomic1, libpulse-dev, libpulse0), built from the server's own docker folder.
Machine	AMD Ryzen 9 5950X, Proxmox VE 9, each game server in Docker inside a dedicated LXC container. 8 GB memory limit, no swap.
Command	`./valheim_server.x86_64 -nographics -batchmode -name "gatergrid-lab" -port 2456 -world "Lab" -password (random) -public 0`

Changes from defaults

No -crossplay. Official start script has it; routes traffic via Microsoft's PlayFab relay.
-public 0: kept off the public server list.
Random 12-character password.

Full method

Sources

Valheim Dedicated Server Instruction Manual (ships with the server download)
Iron Gate: A guide to dedicated servers