Demo Validating Backup

In this guide, we’ll walk through manually backing up your Jenkins home directory and validating the archive in an isolated environment. This process helps ensure you can fully restore Jenkins configuration, jobs, plugins, and credentials in the event of a failure.

1. Locate the Jenkins Home Directory

List the contents of /var/lib and filter for “jenkins” to identify the home directory and any existing backups:

root@host:/var/lib# ls | grep -i jenkins
drwxr-xr-x 28 jenkins jenkins    12288 Feb  7 07:05 jenkins/
-rw-r--r--  1 root    root 2209944892 Feb  3 09:00 jenkins-EOF.tar.gz
drwxr-xr-x 10 jenkins jenkins     4096 Feb  3 08:59 jenkins.bak/

You should see:

jenkins/ – the active Jenkins home directory.
Any previous archives like jenkins-EOF.tar.gz.

The default Jenkins home path is /var/lib/jenkins.

2. Create a Compressed Backup

Use tar to archive and compress the entire Jenkins home directory, saving it under /tmp with a timestamped filename:

root@host:/var/lib# tar -zcvf \
  /tmp/jenkins_home-$(date +"%Y%m%d%H%M").tar.gz \
  jenkins

This command will:

Recursively package jenkins/.
Compress the archive (.tar.gz).
Name it with the current date and time (e.g., 202502070714).

Using a timestamp in your backup filename (e.g., $(date +"%Y%m%d%H%M")) makes tracking and rotating archives much easier.

Depending on the data size, this may take a few minutes.

3. Verify the Backup Archive

After the tar command completes, confirm the archive exists and check its size:

root@host:/var/lib# ls -lh /tmp/jenkins_home-*.tar.gz
-rw-r--r-- 1 root root 2.0G Feb  7 07:17 /tmp/jenkins_home-202502070714.tar.gz

A few gigabytes is common for Jenkins installations with extensive job history and plugins.

4. Prepare a Test Environment

To validate the integrity of your backup without impacting production, create a sandbox copy:

Stop the Jenkins service to avoid data changes during copy.
Copy the home directory to /tmp/jenkins-backup.
Inspect the backup contents.

4.1 Stop Jenkins

Stopping the production Jenkins service may interrupt active builds. Perform this step during a maintenance window.

root@host:/var/lib# systemctl stop jenkins

4.2 Extract or Copy

root@host:/var/lib# cp -r jenkins /tmp/jenkins-backup
root@host:/var/lib# cd /tmp/jenkins-backup
root@host:/tmp/jenkins-backup# ls
config.xml    jobs/       plugins/    secrets/    users/
queue.xml     scriptApproval.xml  tools/    updates/    workspace/

Common subdirectories in a Jenkins home backup:

Subdirectory	Contents
config.xml	Main Jenkins configuration file
jobs/	Job definitions & build history
plugins/	Installed plugins
secrets/	Credentials and secret storage
users/	User accounts and permissions
updates/	Update-center metadata
workspace/	Active build workspaces

5. Point a Jenkins Instance at the Backup

Launch a standalone Jenkins instance using your sandboxed backup directory as JENKINS_HOME:

Export the environment variable:

root@host:/tmp/jenkins-backup# export JENKINS_HOME=/tmp/jenkins-backup

Run the Jenkins WAR on a non-standard port (e.g., 9999):

root@host:~# cd ~/jenkins-war
root@host:~/jenkins-war# java -jar jenkins.war --httpPort=9999

Monitor startup output:

Running from: /root/jenkins-war/jenkins.war
Webroot: /tmp/jenkins-backup/war
2025-02-07 07:21:04.103+0000 [id=1]  INFO  winstone.Logger#logInternal:
  Beginning extraction from war file
2025-02-07 07:21:05.357+0000 [id=1]  INFO  hudson.WebAppMain#contextInitialized:
  Jenkins home directory: /tmp/jenkins-backup found at: EnvVars.masterEnvVars.get("JENKINS_HOME")
2025-02-07 07:21:11.141+0000 [id=33] INFO  jenkins.lifecycle.Lifecycle#onReady:
  Jenkins is fully up and running

6. Validate in the Browser

Open your browser and navigate to:

http://<host>:9999

You should see the Jenkins login screen. After authentication, verify that:

All your jobs are listed.
Plugin manager shows installed plugins.
Credentials, system configurations, and user accounts match production.

This successful validation confirms that your backup archive is complete and restorable.

Introduction and Basics

Jenkins Setup and Interface

Extending Jenkins and Administration

Jenkins Pipelines

Automation and Security

Setting up CI Pipeline

Code Quality and Testing

Containerization and Deployment

Kubernetes and GitOps

AWS Lambda and Advanced Deployment Techniques

Jenkins Administration and Monitoring - Part 1

Shared Libraries in Jenkins

Agents and Nodes in Jenkins

Pipeline Enhancement and Caching

Pipeline Structure and Scripted vs Declarative

Jenkins Administration and Monitoring - Part 2

Backup and Configuration Management

Demo Validating Backup

1. Locate the Jenkins Home Directory

2. Create a Compressed Backup

3. Verify the Backup Archive

4. Prepare a Test Environment

4.1 Stop Jenkins

4.2 Extract or Copy

5. Point a Jenkins Instance at the Backup

6. Validate in the Browser

Links and References

Watch Video

​1. Locate the Jenkins Home Directory

​2. Create a Compressed Backup

​3. Verify the Backup Archive

​4. Prepare a Test Environment

​4.1 Stop Jenkins

​4.2 Extract or Copy

​5. Point a Jenkins Instance at the Backup

​6. Validate in the Browser

​Links and References

Watch Video

1. Locate the Jenkins Home Directory

2. Create a Compressed Backup

3. Verify the Backup Archive

4. Prepare a Test Environment

4.1 Stop Jenkins

4.2 Extract or Copy

5. Point a Jenkins Instance at the Backup

6. Validate in the Browser

Links and References