Valheim Deep North 1.0 — Safe Server Migration Guide
With Valheim's Deep North 1.0 in public beta since January 2026 and the full "1.0 Gold" release expected mid-2026, long-running dedicated servers face their most significant upgrade challenge since Mistlands. Large world files, built-in networking changes, and obsolete mods all need attention before you flip the version switch. This guide covers every step.
Why This Migration Is Riskier Than Previous Biome Updates
Valheim generates new biome chunks on first load after an update. Deep North is the final biome — the largest and most demanding. On servers with world files above approximately 50 MB, the biome generation phase can corrupt the save if:
- The process is interrupted (crash, OOM kill, or admin panic-restart)
- Available disk space is insufficient for the expanded world file
- Incompatible mods are still loaded during first boot
The generation happens exactly once on first load with the new version. If it completes cleanly, subsequent starts are normal.
Step 1 — Audit Your World File Size
Locate your world files (default paths):
# Linux server
~/.config/unity3d/IronGate/Valheim/worlds/
/path/to/valheim/worlds/
# Files to check
WORLDNAME.db ← main world file
WORLDNAME.db.old ← previous backup (keep this)
WORLDNAME.fwl ← world metadata
Check the size of WORLDNAME.db. Worlds with 3+ years of active play commonly reach 100–300 MB. Ensure your server has at least 3× the world file size in free disk space before upgrading — the generation process writes intermediate files.
Step 2 — Take a Layered Backup
Before any upgrade, create backups at three layers:
Layer 1 — Local copy
Copy all world files to a dated folder on the server: worlds_backup_2026-MM-DD/. Do this while the server is stopped to avoid a partial write.
Layer 2 — Off-server copy
Download the backup to your local machine or a cloud storage bucket. If the server disk fails during generation, the local copy is worthless.
Layer 3 — Version pin
Note the exact Valheim server version you're running before upgrading. Steam stores previous versions — you can roll back if the migration fails.
Step 3 — Remove Legacy Networking Mods
This is critical. Valheim 1.0 integrates the Better Networking engine directly into the core game. The popular Better Networking mod (and forks) are now redundant and will conflict with the built-in implementation.
Mods to remove or disable before upgrading:
- Better Networking and any fork
- Any mod that patches
ZNet,ZRoutedRpc, or compression-layer functions - Mods that modify the default MTU or packet batching behavior
If you're using BepInEx, move conflicting mods out of the BepInEx/plugins/ folder rather than deleting them — you may need to confirm compatibility before re-adding.
Step 4 — The Upgrade Sequence
- Stop the server — do not update while players are connected
- Verify all backups are complete and accessible
- Remove or disable legacy networking mods
- Update the Valheim server via SteamCMD:
steamcmd +login anonymous +app_update 896660 validate +quit - Start the server — let it run the Deep North generation without interruption. On a fast SSD with a large world this takes 2–8 minutes. On spinning disk it can take 20+ minutes.
- Watch the server log for
World savedafter the generation completes - Test with a single admin connection before opening to players
Step 5 — PS5 Crossplay Configuration
Valheim 1.0 launches with full crossplay: PC (Steam), Xbox, and PlayStation 5. For dedicated servers, crossplay is enabled by default. To explicitly control it:
# In valheim_server startup arguments
-crossplay ← enables cross-platform matchmaking (default in 1.0)
-noCrossplay ← restrict to Steam-only players
What Happens to Existing World Progress
- All existing biome progress (Meadows through Ashlands) is preserved
- Player character files are fully compatible — no character reset
- Deep North terrain generates in unexplored areas only — explored land is untouched
- Ashlands content and gear carry forward without changes
Post-Migration Health Check
| Check | How |
|---|---|
| World loaded cleanly | Log shows "World saved" after first boot |
| No mod conflicts | No BepInEx errors in server log on startup |
| Crossplay working | Test with a PS5 or Xbox account joining the server |
| Performance baseline | Compare tick rate before/after — Deep North adds new entity simulation |
| Backup retained | Confirm pre-upgrade backup is still accessible off-server |
Running Valheim on Supercraft means automated pre-update snapshots, one-click version rollback, and built-in crossplay support from day one of the 1.0 release.