How to Host a Valheim 1.0 Dedicated Server with Docker on Ubuntu Server

This guide sets up a Valheim 1.0 dedicated server on Ubuntu Server with Docker, using your existing world and BepInEx mods. The Docker image updates the server automatically and backs up the world every hour.

Valheim 1.0 (released September 9, 2026) changed how worlds are saved. Older guides that tell you to upload a .db and .fwl file pair are out of date.

What you need

Item	Recommendation
Virtual machine	Hyper-V (or any hypervisor) running Ubuntu Server
CPU	2 cores minimum, 4 fast cores recommended
RAM	4 GB minimum, 8 GB recommended, fixed (turn off Hyper-V Dynamic Memory)
Disk	10 GB free or more for the server, world and backups
IP address	A static IP or DHCP reservation for the VM
Windows PC	Valheim on Steam, plus PowerShell or WinSCP to copy files
SSH access	You can log in to the VM as a normal user with `sudo`

Throughout this guide, replace youruser with your Ubuntu username and 192.168.1.50 with your VM’s IP address. Valheim does most of its work on one thread, so a few fast cores beat many slow ones.

Step 1: Install Docker and give your user access

Install Docker from Docker’s official script rather than Ubuntu’s docker.io package, so you get Docker Compose v2 included:

curl -fsSL https://get.docker.com | sudo sh

Add your user to the docker group so you can run Docker without sudo:

sudo usermod -aG docker youruser

The group change only applies to new logins. Log out and SSH back in (or run newgrp docker for the current terminal), then check it:

groups
docker ps

groups should list docker, and docker ps should print an empty table. If you skip this step you will see permission denied while trying to connect to the docker API at unix:///var/run/docker.sock.

Step 2: Create the server folders

Create the folders as your own user before the container ever runs. If Docker creates them first, they end up owned by root and your uploads fail with “permission denied.”

mkdir -p ~/valheim/config/worlds_local ~/valheim/config/bepinex/plugins ~/valheim/data

When you’re done, the folders look like this:

~/valheim/
├── docker-compose.yml
├── config/                 (mounted as /config)
│   ├── worlds_local/
│   │   └── YourWorld/      (your world folder goes here)
│   └── bepinex/
│       └── plugins/        (mod .dll files go here)
└── data/                   (server files, downloaded automatically)

Step 3: Find your world on your Windows PC

In Valheim 1.0, a world is a folder named after the world, not a .db and .fwl pair. Inside it you will find files like these:

File	What it is
`_main.N.fwl2`	World metadata (name, seed), replaces the old `.fwl`
`_main.N.db2`	World data, replaces the old `.db`
`_main.N.chunks`	Index of the terrain chunks
`_main.N.ok`	Marker that the last save finished cleanly
`*.chunk`	Terrain chunks, more appear as the world is explored

The N is a save counter (for example _main.7.db2). Never rename these files.

There are two places the world can be, depending on whether it is a local or Steam Cloud save. Close Valheim before you look.

Local saves. Press Win+R and paste:

%userprofile%\AppData\LocalLow\IronGate\Valheim\worlds_local

If the world folder there only contains cacheMinimap... files, that is just a minimap cache. Your real world is in Steam Cloud.

Steam Cloud saves. Press Win+R and paste:

C:\Program Files (x86)\Steam\userdata

Open the numbered folder (your Steam account ID), then 892970\remote\worlds. Your world folder, with the _main.N.* and .chunk files, is there. If you have several numbered folders, check each one.

Alternatively, in Valheim go to Start Game, pick your world, choose Manage Saves and move it to local storage.

If you can’t find the world in either place, it may have been hosted on a friend’s PC. Valheim creates a minimap cache for worlds you join, but the world itself lives on the host’s machine.

Step 4: Upload the world folder and mods

Upload the whole world folder, never individual files out of it. Close Valheim and Steam first so cloud sync doesn’t change files mid-copy. You can upload before the server has ever run. The container picks up the world on its first start.

Option A: PowerShell (built into Windows 11). Change into the folder that holds your world folder, then copy it with -r:

cd "C:\Program Files (x86)\Steam\userdata\<SteamID>\892970\remote\worlds"
scp -r YourWorld youruser@192.168.1.50:~/valheim/config/worlds_local/

For a local save, use cd "$env:USERPROFILE\AppData\LocalLow\IronGate\Valheim\worlds_local" instead. Quoting the path handles spaces in Windows usernames.

Option B: WinSCP. Connect with the SFTP protocol to your VM’s IP using your Ubuntu login. Browse on the right to /home/youruser/valheim/config/worlds_local/ and drag the whole world folder over from the left.

Mods. If you already play with BepInEx mods on Windows, they’re in your game folder:

C:\Program Files (x86)\Steam\steamapps\common\Valheim\BepInEx\plugins

Copy everything in that folder to ~/valheim/config/bepinex/plugins/ on the server, both the loose .dll files and the mod folders (EpicLoot, Jotunn and so on). Don’t upload BepInEx itself. The container installs it. Every mod needs a version updated for Valheim 1.0.

This PowerShell script copies them all in one go. Save it as Copy-ValheimMods.ps1 in a folder like Downloads, not inside the plugins folder, or it will upload itself along with the mods. Change $Server and $User to match your VM.

param(
    [string]$Server      = "192.168.1.50",
    [string]$User        = "youruser",
    [string]$ValheimPath = "C:\Program Files (x86)\Steam\steamapps\common\Valheim",
    [string]$RemotePath  = "~/valheim/config/bepinex/plugins/",
    [switch]$Restart
)

$plugins = Join-Path $ValheimPath "BepInEx\plugins"
if (-not (Test-Path -LiteralPath $plugins)) { Write-Error "Plugins folder not found: $plugins"; exit 1 }

$items = @(Get-ChildItem -LiteralPath $plugins | ForEach-Object { $_.FullName })
if ($items.Count -eq 0) { Write-Error "No mods found in $plugins"; exit 1 }
Write-Host "Found $($items.Count) items to copy."

ssh "$User@$Server" "mkdir -p $RemotePath"
if ($LASTEXITCODE -ne 0) { Write-Error "Could not connect to $Server"; exit 1 }

scp -r @items "${User}@${Server}:$RemotePath"
if ($LASTEXITCODE -ne 0) { Write-Error "Copy failed (scp exit code $LASTEXITCODE)"; exit 1 }
Write-Host "Copy complete."

if ($Restart) { ssh "$User@$Server" "cd ~/valheim && docker compose restart" }

Run it from the folder you saved it in. -ExecutionPolicy Bypass gets past Windows blocking downloaded scripts, and -Restart restarts the container afterward if the server is already running.

powershell -ExecutionPolicy Bypass -File .\Copy-ValheimMods.ps1

The script copies the mods but not their settings in BepInEx\config. The server creates default config files on its first start.

Check the upload on the VM:

ls ~/valheim/config/worlds_local/YourWorld

You should see the _main.N.* and .chunk files directly inside it. If you see another YourWorld folder instead, it got nested one level too deep. Move its contents up one level.

Step 5: Create docker-compose.yml

This guide uses ghcr.io/community-valheim-tools/valheim-server. It replaced the lloesche image (the old GitHub link redirects there) and supports the 1.0 world format, including backups.

Create the file with nano ~/valheim/docker-compose.yml and paste:

services:
  valheim:
    image: ghcr.io/community-valheim-tools/valheim-server
    container_name: valheim
    cap_add:
      - sys_nice
    ports:
      - "2456-2457:2456-2457/udp"
    volumes:
      - ./config:/config
      - ./data:/opt/valheim
    environment:
      SERVER_NAME: "My Valheim Server"
      WORLD_NAME: "YourWorld"
      SERVER_PASS: "changeme123"
      SERVER_PUBLIC: "false"
      TZ: "America/Chicago"
      BACKUPS: "true"
      BACKUPS_MAX_AGE: "7"
      BEPINEX: "true"
    restart: unless-stopped
    stop_grace_period: 2m

Setting	What to put
`WORLD_NAME`	The exact name of your world folder, case-sensitive. A mismatch makes the server generate a brand-new world.
`SERVER_PASS`	At least 5 characters, and not contained in `SERVER_NAME`, or the server refuses to start.
`SERVER_PUBLIC`	`false` keeps it out of the public server list; friends join by IP.
`TZ`	Your time zone, used for backup and restart times.
`BEPINEX`	`true` installs BepInEx and loads mods from `config/bepinex/plugins`. Remove it for a vanilla server.
`stop_grace_period`	Gives the server time to finish saving when you stop it.

Leave crossplay off when using mods. Crossplay clients (Xbox, Game Pass) can’t run BepInEx mods. If one of your mods uses RPC and needs an extra port, change the port line to "2456-2458:2456-2458/udp".

The container checks for Valheim updates every 15 minutes and restarts only when nobody is online, so the server keeps up with Steam on its own. Backups land in config/backups every hour.

Step 6: Start the server and watch the logs

cd ~/valheim
docker compose up -d
docker compose logs -f

The first start takes several minutes while the container downloads about 1 GB of server files from Steam, then BepInEx. Press Ctrl+C to stop following the logs. The server keeps running.

What to look for:

BepInEx loading each of your plugins by name.
The server loading your world name, not generating a new one.
Game server connected, which means it’s ready for players.

Common commands:

Task	Command
Stop the server (saves first)	`docker compose down`
Restart it	`docker compose restart`
Update the container image	`docker compose pull && docker compose up -d`
Check it’s running	`docker ps`

Uploading files later

Stop the server before you replace world files, so it can’t save over them mid-copy:

cd ~/valheim
docker compose down
docker ps

When valheim no longer shows in docker ps, upload your files, then start it again with docker compose up -d. Mods only load when the container starts, so new mods just need a restart.

The container runs as root, so once the server has run, the folders it created under config belong to root and your uploads fail with “Permission denied.” Take ownership back before uploading:

sudo chown -R youruser:youruser ~/valheim/config
ls -ld ~/valheim/config/bepinex/plugins

The second command should show your username instead of root. New files the container writes later, like backups and mod configs, are root-owned too, so run the chown again whenever an upload is refused.

Step 7: Connect, firewall and port forwarding

Join the server. In Valheim, go to Join Game, click Join IP and enter your VM’s IP (for example 192.168.1.50). You don’t need to enter the port if you kept 2456. Join IP works even with SERVER_PUBLIC set to false. The Steam server browser does not.

Firewall on the VM. If ufw is enabled, open the game ports:

sudo ufw allow 2456:2457/udp

Friends outside your network. On your router, forward UDP ports 2456-2457 to the VM’s IP. Friends then use Join IP with your public IP address. Keep the VM’s IP static, or the forward breaks the next time it changes.

Mods on clients. Everyone who joins needs the same mods at the same versions installed in their own game, or they’ll be kicked or desync. Players also need the same Valheim version as the server, which the container keeps current.

Troubleshooting

Symptom	Fix
`permission denied ... /var/run/docker.sock`	Your user isn’t in the `docker` group yet. Run `sudo usermod -aG docker youruser`, then log out and back in (Step 1).
`scp` says `Permission denied` or `stat remote: No such file or directory`	The container created those folders as root. Run `sudo chown -R youruser:youruser ~/valheim/config`, then upload again.
The mod copy script uploads itself	The script is saved inside `BepInEx\plugins`. Move it to another folder like Downloads and run it from there.
Server generates a new, empty world	`WORLD_NAME` doesn’t exactly match the world folder name, or the folder is nested (`YourWorld/YourWorld/`). Stop, fix, start again.
Server won’t start at all	Check that `SERVER_PASS` is 5+ characters and not part of `SERVER_NAME`. Then move the files out of `config/bepinex/plugins` and start vanilla to see whether a mod is the cause.
Players can’t join from outside	Confirm UDP 2456-2457 is forwarded to the VM and open in `ufw`, and that they’re using Join IP with your public IP.
“Incompatible version” when joining	The client and server are on different Valheim versions. Wait for the container’s update check, or run `docker compose restart`.
Old world (pre-1.0) instead of a folder	Upload the `.db` and `.fwl` pair into `worlds_local` and set `WORLD_NAME` to the file name without extension. The server converts it to the 1.0 folder format on first load and keeps a backup. Conversion is one-way.

Keep a copy of your world on your PC until you’ve confirmed the server loads it correctly.

Sources