Upgrade & backup

Two things you should do regularly. Both take minutes.

What to back up

Three things matter:

Item	Where	Why
The server database	/data/mumble-server.sqlite (in the volume)	Channels, users, ACLs, chat history.
The file storage	/data/file-server-storage/ (in the volume)	Avatars, emotes, attachments.
Your .env file	on the host	Server settings, secrets.

The whole /data volume covers items 1 and 2. Back up the host-side config separately.

Back up

The simplest approach is to stop the server, copy the volume, and restart:

1. Stop the server:

   docker compose stop mumble-server

2. Copy the volume:

   docker run --rm \
     -v mumble-data:/source:ro \
     -v "$(pwd)":/dest \
     alpine \
     tar -czf /dest/mumble-backup-$(date +%F).tar.gz -C /source .

3. Restart the server:

   docker compose start mumble-server

4. Also back up your .env:

   cp .env "/secure/place/.env-mumble-$(date +%F)"

You can also back up without stopping if you accept the small risk of an inconsistent SQLite snapshot. For production it is safer to stop briefly.

Schedule it

A cron job that runs the steps above weekly is enough for most servers. Adjust the retention to your taste:

/etc/cron.weekly/mumble-backup

#!/bin/bash
set -e
cd /srv/mumble
docker compose stop mumble-server
docker run --rm \
  -v mumble-data:/source:ro \
  -v /backups/mumble:/dest \
  alpine \
  tar -czf /dest/mumble-$(date +%F).tar.gz -C /source .
docker compose start mumble-server
find /backups/mumble -mtime +60 -delete

Make it executable and you are done.

Restore from a backup

1. Stop the server:

   docker compose stop mumble-server

2. Remove the existing volume:

   docker volume rm mumble-data
   docker volume create mumble-data

3. Restore:

   docker run --rm \
     -v mumble-data:/dest \
     -v "$(pwd)":/source \
     alpine \
     tar -xzf /source/mumble-backup-2026-05-01.tar.gz -C /dest

4. Start the server:

   docker compose start mumble-server

5. Reset the SuperUser password if needed:

   docker exec mumble-server mumble-server \
     --ini /data/mumble_server_config.ini \
     --set-su-pw "new-password"

Upgrade

The official image is published to ghcr.io/fancy-mumble/mumble-server:latest.

1. Take a backup (see above).

2. Pull the new image:

   docker compose pull mumble-server

3. Recreate the container:

   docker compose up -d mumble-server

4. Watch the logs for migration messages:

   docker compose logs -f mumble-server

5. Connect with a client and sanity-check that channels, chat history, and avatars are all there.

Pin a version

For production, pin to a specific tag instead of latest:

image: ghcr.io/fancy-mumble/mumble-server:1.6.1

That way you control when you upgrade.

Rollback

If an upgrade goes wrong:

1. Stop the server.
2. Restore the previous backup (see “Restore” above).
3. Set the image back to the previous tag.
4. Start the server.

The database schema is only ever added to in minor versions, never removed, so rolling back the binary is safe as long as you also restore the database.

Migrating to a new host

1. On the old host: stop the server, take a backup.
2. Copy the backup file and .env to the new host.
3. On the new host: install Docker, copy your docker-compose.yml, restore from the backup, start the server.
4. Update DNS to point at the new host.
5. Once you have confirmed it works, retire the old server.

If you also change the public IP, update webrtcsfupublicip in your config or screen sharing will be broken until you do.

Database growth

The two big spenders are persistent chat and link previews:

• Lower pchatdefaultretentiondays to clear out old messages.
• Lower plugin.file-server.retentionDays to clear out old files.

Then run VACUUM once to reclaim space:

docker exec mumble-server sqlite3 /data/mumble-server.sqlite "VACUUM;"

What if the database is corrupted?

Restore from the most recent backup. Mumble’s SQLite database is normally robust, but a disk failure or a sudden power-cut can truncate it. Backups are your friend.

Next step

You are done with the server section. Continue with the admin pages to learn how to manage users, channels, and permissions:

• SuperUser & first login
• Channels
• Roles & permissions