One of the best features that makes online backup incredibly practical is their use of the Incremental Foreverparadigm. In order to understand what an Incremental Forever paradigm is, let’s take a look at the way backups were previously done.
Because data is constantly changing, multiple copies of all files must be kept on-hand in case an older historical file version needs to be restored or rolled back. Although an obvious solution would be to create a new backup tape every day, this was a slow and expensive process.
The main problem with this methodology was that you had to copy lots of redundant data, while blocking access to the computer while the backup window was taking place.
In order to fix this problem, 2 incremental backup paradigms were created: Differential Incremental and Cumulative Incremental.
With the Cumulative Incremental approach, a full system backup is performed once per cycle. (A cycle is usually 30 or 40 days) After that, a daily incremental backup is performed. This incremental backup only contains the data which has changed since first full backup was performed. At the end of the cycle, a new full backup is made and the process starts over from the beginning.
Although the Cumulative Incremental paradigm offered fast, simple recovery, the backups would start to get very large towards the end of the cycle. Large backups eat up lots of expensive storage, and create long backup windows where the computer can’t be used.
The Differential Incremental was designed as a time-saving and space-saving improvement over the Cumulative Incremental paradigm. With this approach, you still have the first full backup at the beginning of the backup cycle. But every subsequent incremental backup only copies changes from the previous day.
Although this approach was much faster and more economical than the Cumulative Incremental approach, it still had one major drawback. The emergency recovery process was much slower and more error-prone because there were so many different backup fragments to track and load.
If you had to recover a backup from day 15 of the backup cycle, you’d have to load 16 different backup tapes: the first full backup from day 0, and the following 15 incremental backups which made up the final active version.
The Incremental Forever paradigm is a software-based approach that combines the best of both worlds. You get the elegance and simplicity of the Cumulative Incremental paradigm with the speed and efficiency of the Differential Incremental paradigm.
An Incremental Forever backup only requires a single full backup of your data. After that, you can perform perpetual incremental backups without ever requiring another full backup. (Hence the name Incremental Forever)
This approach works by taking your latest incremental backup and using software to combine it with your most recent full backup version. And every day, the latest incremental version is appended to the previous day’s backup to artificially form a new full backup.
From the end-user’s perspective, it will appear as if you just created a new full backup every day. However, the backup server is smart enough not to store any of the duplicated data. This way, 30 days worth of full daily backup copies each 10GB in size will only amount to 11 GB in total storage.
But in the event that you need to recover, you can just pull whichever full backup copy is required without worrying about managing multiple tapes.
When this methodology is delivered as part of an online backup service, it has 3 main benefits:
- Faster, simpler recovery
- Fully automated backups with minimal backup windows
- No backup tapes to fiddle with or ship off-site
If you’ve grown tired of the manual labor involved in full daily backups, Cumulative Incremental backups, or Differential Incremental backups, you may want to consider automating your data protection using an online backup service with Incremental Forever technology.
About The Author: Storagepipe Solutions is celebrating their tenth year as the leading Canada online backup provider.