Migrating Jenkins to Another Node

In this guide, you will learn how to migrate a Jenkins controller from one virtual machine (Node) to another. We’ll walk through stopping the service, backing up the Jenkins home directory, transferring it to the new Node, and bringing Jenkins back online—preserving all jobs, plugins, and configurations.

1. Scenario

• Source Jenkins controller
  IP: 64.227.x.x
  Fully configured and running jobs.

• Target VM
  IP: 165.232.x.x
  Fresh Jenkins install on Ubuntu with Docker & JDK 17.

2. Pre-migration Checklist

Before you begin, make sure both Nodes meet these requirements:

3. Back Up Jenkins Home on Source Node

On the source Node, $JENKINS_HOME is typically /var/lib/jenkins. Follow these steps:

1. Stop and disable Jenkins:

   sudo systemctl stop jenkins
   sudo systemctl disable jenkins
   

2. Verify it’s inactive:

   sudo systemctl status jenkins
   # Should show: Active: inactive (dead)
   

3. Create a compressed backup:

   cd /var/lib
   sudo tar -zcvf jenkins-backup.tar.gz jenkins
   

Once jenkins-backup.tar.gz is ready, transfer it to the target Node.

4. Transfer Backup to Target Node

From the source Node, use scp to copy the archive:

scp /var/lib/jenkins-backup.tar.gz [email protected]:/tmp/

Enter the root password when prompted. Then SSH into the target Node to proceed.

5. Prepare the Target Node

1. Stop and disable the existing Jenkins service:

   sudo systemctl stop jenkins
   sudo systemctl disable jenkins
   

2. Confirm it’s stopped:

   sudo systemctl status jenkins
   # Active: inactive (dead)
   

If you browse to Jenkins now, you may see the setup screen:

Optional: Backup Current Jenkins on Target

If you want to keep the default install:

cd /var/lib
sudo tar -zcvf jenkins-original-backup.tar.gz jenkins
sudo rm -rf jenkins

6. Restore Backup on Target Node

1. Move and extract the backup:

   sudo mv /tmp/jenkins-backup.tar.gz /var/lib/
   cd /var/lib
   sudo tar -zxvf jenkins-backup.tar.gz
   

2. Fix ownership:

   sudo chown -R jenkins:jenkins jenkins
   

7. Start Jenkins on Target Node

Re-enable and launch Jenkins:

sudo systemctl enable jenkins
sudo systemctl start jenkins
sudo systemctl status jenkins
# Should show: Active: active (running)

Refresh your browser on http://165.232.x.x:8080/. All your jobs, plugins, and settings will appear exactly as before.

Links and References

• Jenkins Official Documentation
• Backing Up and Restoring Jenkins
• Using SSH for Secure Connections