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How 'Incremental Forever-Virtual Full' Can Transform Backup

If you’ve been frustrated by the limitations of incremental backups and differential backups for the enterprise, an “incremental forever/virtual full” approach may make sense for your organization.

Industry Perspectives

October 9, 2017

4 Min Read
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Steve Pao is CMO for Igneous.

Enterprise data backup continues to employ a complex mix of full, incremental, and differential backups. What's involved with these backup choices? Is there a data backup option that's more advanced? 

Popularized by consumer backup applications, such as Apple’s Time Machine, an emerging method is “incremental forever” backup with “virtual full” recoveries. It’s a significant improvement from traditional full backups and even from the more advanced incremental and differential backups.

Full backups of all of an enterprise’s data take time. So much time that often, IT must reschedule backups because the backups slow the primary server and business users complain.

Intended to fix that problem, incremental backups preserve only the data that’s changed since your last backup. It sounds like a smart alternative to full backups that tax IT staff and data storage. However, all it takes is one lost tape, one spilled coffee or one media error for you to end up with no backup at all.

Differential backup solves the problem of cascading incremental backups. On Monday, for instance, you backup the difference between Sunday and Monday. On Tuesday, you backup the difference between Sunday and Tuesday. But by Friday, when you’re backing up the difference between Sunday and Friday, your backups are almost as big as they would be if you were taking a full backup!

That’s where an “incremental forever/virtual full” approach comes into play. Backups are created incrementally and continuously, but the backup is internally reconstructed as a “virtual full” backup, making data recovery possible in a single step. This approach offers several of the benefits of these other methods for your data backups without the pain of data recovery.

Value #1 - Restore Data After Disasters Strike

“Incremental forever” with “virtual full” is “incremental forever” without the pain of data recovery. That’s because “virtual full” always presents your data back to you as a full backup.

For example, if a ransomware attack corrupted your data files, you would likely need to restore everything. What you don’t want to have to do is figure out when the last full backup occurred and rebuild your data from multiple incremental backups. Instead, you want your data history recreated for you. That’s the effortless magic of “virtual full.”

Value #2 - Minimize the Impact to Your Primary Storage

IT initially turned to incremental backups and differential backups to try to diminish the strain on the primary filers and minimize the noticeable impact to business users. In general, a higher rate of changes since the last backup adds more strain to the primary filer.

The trade-off has always been frequency of incremental backups versus pain of recovery. Traditionally, IT had to schedule nightly backup windows for incremental backups. Full backups were generally reserved for weekends, when longer backup windows could typically be scheduled. In this scenario, a recovery could take a full recovery, plus five weekday increments.

By eliminating the pain of recovery, backups can run more frequently - in essence, continuously. By reducing the change rate associated with each backup operation, data transfers can be easily smoothed out, minimizing impact to primary filers. My company, Igneous Systems, takes this concept a step further through dynamic throttling when file systems are in use by users or applications, eliminating impact to primary filers.

Value #3 - Eliminate Backup Windows

Once you eliminate the performance impact to primary filers and run backups continuously, users or applications should not be affected by backup operations at any time. You’ve essentially eliminated the backup window.

A large semiconductor manufacturer with which I’m very familiar, for example, can now run its most problematic backups while users and applications access the system and are none the wiser. This means the admins don’t field calls from unhappy end users and cancel backups because of their impact on users and applications.


Enterprises now have more backup options than ever. Consider which one makes the most sense for your organization. If you’ve been frustrated by the limitations of incremental backups and differential backups for the enterprise, an “incremental forever/virtual full” approach may make sense for your organization.

Opinions expressed in the article above do not necessarily reflect the opinions of Data Center Knowledge and Informa.

Industry Perspectives is a content channel at Data Center Knowledge highlighting thought leadership in the data center arena. See our guidelines and submission process for information on participating. View previously published Industry Perspectives in our Knowledge Library.


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