The Backup Fork TTL setting is used to set a time limit on the. forked backup processes of JetBackup. This can allow you to keep backups running within a specific time frame. This can be helpful if your server resources are limited during certain times of the day.
Before enabling a Backup Fork TTL, please note that enabling this and setting a value that is too short, will result in backups not completing. Please be sure you are checking the backup logs to ensure your backups are completing within the set TTL.
To set this option and adjust it you will need to click on JetBackup within WHM.
Then click on Settings.
Next click on the Performance tab.
Then you will see the Backup Fork TTL option. You can click the dropdown menu to select a value from disabled to 10 hours. If you need to set it for a longer time you can select the Custom option.
After making your change, be sure you click the Save button.
For additional details on the JetBackup Settings please see the documentation: