!!! warning This guide assumes you intend to migrate an existing mailcow server (source) over to a brand new, empty server (target). It takes no care about preserving any existing data on your target server and will erase anything within `/var/lib/docker/volumes` and thus any Docker volumes you may have already set up. !!! tip Alternatively, you can use the `./helper-scripts/backup_and_restore.sh` script to create a full backup on the source machine, then install mailcow on the target machine as usual, copy over your `mailcow.conf` and use the same script to restore your backup to the target machine. **1\.** Follow the [installation guide](i_u_m_install.en.md) to install Docker and Compose. **2\.** Stop Docker and assure Docker has stopped: ``` systemctl stop docker.service systemctl status docker.service ``` **3\.** Run the following commands on the source machine (take care of adding the trailing slashes in the first path parameter as shown below!) - **WARNING: This command will erase anything that may already exist under `/var/lib/docker/volumes` on the target machine**: ``` rsync -aHhP --numeric-ids --delete /opt/mailcow-dockerized/ root@target-machine.example.com:/opt/mailcow-dockerized rsync -aHhP --numeric-ids --delete /var/lib/docker/volumes/ root@target-machine.example.com:/var/lib/docker/volumes ``` **4\.** Shut down mailcow and stop Docker on the source machine. === "docker compose (Plugin)" ``` bash cd /opt/mailcow-dockerized docker compose down systemctl stop docker.service ``` === "docker-compose (Standalone)" ``` bash cd /opt/mailcow-dockerized docker-compose down systemctl stop docker.service ``` **5\.** Repeat step 3 with the same commands. This will be much quicker than the first time. **6\.** Switch over to the target machine and start Docker. ``` systemctl start docker.service ``` **7\.** Now pull the mailcow Docker images on the target machine. === "docker compose (Plugin)" ``` bash cd /opt/mailcow-dockerized docker compose pull ``` === "docker-compose (Standalone)" ``` bash cd /opt/mailcow-dockerized docker-compose pull ``` **8\.** Start the whole mailcow stack and everything should be done! === "docker compose (Plugin)" ``` bash docker compose up -d ``` === "docker-compose (Standalone)" ``` bash docker compose up -d ``` **9\.** Finally, change your DNS settings to point to the target server. Also check the `SNAT_TO_SOURCE` variable in your `mailcow.conf` file if you have changed your public IP address, otherwise SOGo may not work.