Restore Swarm¶

Prerequisites¶

• You must use the same IP as the node from which you made the backup. The command to force the new cluster does not reset the IP in the Swarm data.
• You must restore the backup on the same Mirantis Container Runtime version.
• You can find the list of manager IP addresses in state.json in the zip file.
• If auto-lock was enabled on the old Swarm, the unlock key is required to perform the restore.

Perform Swarm restore¶

1. Shut down the Mirantis Container Runtime on the node you select for the restore:

   systemctl stop docker
   

2. Remove the contents of the /var/lib/docker/swarm directory on the new Swarm if it exists.

3. Restore the /var/lib/docker/swarm directory with the contents of the backup.

   Note: The new node uses the same encryption key for on-disk storage as the old one. It is not possible to change the on-disk storage encryption keys at this time. In the case of a swarm with auto-lock enabled, the unlock key is also the same as on the old swarm, and the unlock key is needed to restore the swarm.

4. Start Docker on the new node. Unlock the swarm if necessary.

   systemctl start docker
   

5. Re-initialize the swarm so that the node does not attempt to connect to nodes that were part of the old swarm, and presumably no longer exist:

   $ docker swarm init --force-new-cluster
   

6. Verify that the state of the swarm is as expected. This may include application-specific tests or simply checking the output of docker service ls to be sure that all expected services are present.

7. If you use auto-lock, rotate the unlock key.

8. Add the manager and worker nodes to the new swarm.

9. Reinstate your previous backup regimen on the new swarm.