Docs · Project Zomboid

Server backups & restore

Every long Project Zomboid run ends the same way if you’re unlucky: a mod update, an unstable patch, or a corrupted save wipes weeks of survival in an instant. Backups are the only thing standing between “roll back an hour” and “start over.” This guide explains why PZ saves are unusually fragile, and how automatic off-site backups and one-click restore protect a world you actually care about.

Why backups matter more for PZ than most games

A Project Zomboid world is a big, live directory of binary map chunks and player data that the server writes to constantly. Several things routine to running a PZ server can leave it unloadable:

Unstable-branch patches. Build 42 multiplayer runs on an actively-moving branch. A patch can change the save format, and a world created on one build may not load cleanly on the next.

Major version jumps. Some updates — a step like 42.19 to 42.20 — are significant enough that the safe path is a full world wipe. Without a backup, that decision costs you the run.

Mod updates. A Workshop mod that changes how it stores data, or that removes content your world depends on, can corrupt the save on next load. This is the most common way a healthy server dies, and it happens with no warning.

In every one of these cases, a recent, off-the-box backup is the difference between a minor annoyance and losing everything. On PZ specifically, it is not optional.

How Forgehold backs up your world

Forgehold takes automatic hot backups every 3 hours — “hot” meaning the server keeps running while the world is captured, so there’s no downtime and no window where players are kicked. Each backup is shipped off-box to object storage (Backblaze B2), not left sitting on the same machine as your server. That last detail is the one that matters most: a backup stored on the same host it’s protecting is worthless the moment that host fails. Off-site backups survive the failure of the box itself.

Retention follows a 7-day grandfather-father-son schedule — frequent recent restore points thinning out to sparser older ones — so you always have both a “five minutes ago” and a “a few days ago” version to fall back to without storing hundreds of copies. You can see the full list, with size and expiry, on your server’s Backups tab, and trigger an extra one any time with Back up now before you do anything risky.

Restore is one click — and reversible

On the Backups tab, every backup has a Restore button. Restoring replaces your server’s current world with the chosen backup. The important safety detail: Forgehold takes an automatic safety snapshot of your current world first, before it overwrites anything. So even a restore is undoable — if you restore the wrong point, the world you replaced is sitting in your Snapshots tab, ready to bring back. Restore is meant to be used calmly, not feared.

Snapshots vs backups — not the same thing

Forgehold gives you two save-protection tools, and it’s worth understanding the difference, because one is a genuine safety net and the other is a quick local scratchpad.

The rule of thumb: snapshots are a quick undo, backups are your real safety net. Reach for a snapshot right before a risky change you expect to reverse in the next few minutes — regenerating a world, testing a config. Rely on backups for anything that would actually hurt to lose, because they’re the only copy that outlives the machine. The Snapshots tab labels this plainly: on-host only, not a real backup.

Bringing a save in — and taking it out

Backups also mean you’re never locked in. The World tab lets you import an existing save from another host by uploading it as a .tar.gz, so you can move a community from wherever it lives today without starting over. And you can export your current world to a downloadable archive at any time — no support ticket, no waiting on anyone. Your world is yours to take.

What to do when your world breaks

If players report they can’t connect, the world won’t load, or something looks corrupted after an update, don’t panic and don’t keep restarting into the broken state. Work through this:

1. Stop making it worse. Every boot into a broken world can overwrite good data. Leave the server down while you sort out the restore point.
2. Identify when it broke. Was it right after a mod promotion, a branch change, or a patch? That tells you which backup to target — the last one from before the change.
3. Open the Backups tab and restore. Pick the most recent backup from before the breakage and hit Restore. Your current (broken) world is safety-snapshotted first, so you lose nothing by trying.
4. If a mod caused it, roll the mod back too. Restoring the world puts the save right, but if a bad mod update is still pinned it can re-break on next load. Use the Mods tab rollback to return to the previous mod set as well.
5. Verify before you reopen. Boot the server, confirm the world loads and your character data is intact, then let players back in.