There are a lot of plugins and tools for performing backups like:
- Backup scheduling plugin - https://www.cloudbees.com/products/cloudbees-jenkins-platform/team-edition/features/backup-scheduling-plugin
- Backup plugin - https://wiki.jenkins-ci.org/display/JENKINS/Backup+Plugin
- thinBackup plugin - https://wiki.jenkins-ci.org/display/JENKINS/thinBackup
- 3rd Party tools (snapshotting, cloning, etc.)
As each of these meets a different requirement in terms of backing up what is the best way to perform a backup of the job configurations and global configurations?