How can you use incremental backups to improve your RPO and RTO?

Incremental backups can improve your RPO (Recovery Point Objective) and RTO (Recovery Time Objective) by reducing the amount of data and time needed for backup and recovery. Unlike full backups that copy all data every time, incremental backups only capture changes made since the last backup. This means quicker backups and faster recovery because you're dealing with smaller data sets. It helps you meet tighter RPO and RTO requirements in case of data loss or system failures.

Incremental backups can significantly improve Recovery Point Objective (RPO) and Recovery Time Objective (RTO) in a disaster recovery scenario. Instead of backing up the entire dataset each time, incremental backups only capture changes made since the last backup. This reduces data transfer and storage requirements, shortening backup times and lowering the risk of data loss. To leverage incremental backups effectively, regularly schedule them between full backups, enabling more frequent capture of changes. This approach ensures that, in the event of a data loss, the system can be restored to a more recent state, minimizing both RPO and RTO.

Incremental backups are indeed a positive for RPO but this is not necessarily the case for RTO. Depending on the method used, incremental backups can significantly increase the complexity of restore jobs by, for example, requiring the use of multiple backup media to restore the required data, or making restoration of some data impossible due to corruption of one or more backups in the chain. To minimise these potential impacts, as well as to ensure the greatest redundancy, each incremental backup should include all data that has changed since the last full backup.

Do incremental backups improve your RTO? The answer is - it depends - mainly on what data needs to be restored, how and where it's been backed up and how many restore points are retained. Incremental backups which include all data changes since the last full backup make for easier restores than ones which don't - because it's possible that a restore can be actioned from a single backup medium. If the data you need to restore is spread across multiple increments and backup media the restore process can become cumbersome and long-winded, especially if those media are linear in nature as is the case with magnetic tape. Greater benefits can be gained by using a reverse-incremental method where changes are injected into a full backup.

Virtualisation, together with the right backup software, facilitates image-based backup of entire volumes. While entire volumes can be restored with comparative ease they can also be mounted, just like any other system disk, facilitating efficient file-level restores using something as basic as copy-and-paste. The right backup software can also facilitate reverse incremental backups where changes are injected into a full backup after the blocks in that backup which will be changed are saved as an incremental recovery point. Thus the last backup is always a full backup. This method is particularly useful where disk-based backups are subsequently rolled down onto tape for offsite storage.