What is differential backup? Everything you need to know

We’ve all seen that scene in a movie where the main character works all night to prepare an assignment, only to have the computer crash before they are able to back it up, causing them to have to restart (pun intended) from scratch.

So, we all know how important data protection, backup, and recovery truly are.

But with so many different types of backup strategies, how can we know which one is best suited for us?

Don’t fret, we’ll help you make sense of all the different types of file backups and which one is the right choice for you!

What is differential backup?

The word “differential” in differential backup comes from the idea that only files that have been altered—or are now different—are copied. So, in simple terms, differential backup is a form of backup where only the data files that have changed since the previous full backup were conducted are copied.

By “changed” we mean any data that has been created, updated, or altered, even just a little bit.

Differential backups, to actually be differential, begin with a full backup. After it’s concluded, they use the original backup as a base point to compare the initial files with the subsequent backups. When files are created or modified, they are flagged so they can be copied in the next differential backup.

If this sounds confusing, worry not—it doesn’t have to be! Here’s an example: let’s say a company completes a full backup on Tuesday. Wednesday’s differential backup will back up all the data that has been amended or created since Sunday’s full backup.

Why is differential backup important?

Differential backups are important for several reasons, the first and main one being that they can save a lot of time as well as storage space!

Because there are most likely going to be significantly fewer changes to the data files compared to the total amount of files within a data repository, a differential backup should take much less time to complete than a full backup.

Not only is conducting a differential backup a big time saver, but because only altered files are flagged and targeted in a differential backup, a lot of storage space can be saved as well.

Why do we need differential backup?

The simplest way to answer why we need differential backups is that they save time and storage.

While these types of backups may be somewhat less secure and may not ensure the highest level of data security the way that full backups do, they make up for it by being practical for companies to perform regularly. Differential backups take up less time and fewer resources.

Many companies and managed service providers (MSPs) rely on differential backups as an alternative method for restoring data while reducing restoration time.

What are the disadvantages of differential backup?

While the benefits of differential backups are clear, there are also some downsides.

Some of the disadvantages include:

• They rely on a previous full backup. Without one, they cannot exist.
• If too many differential backups are performed between full backups, the data size of the differential backup might actually become larger than the initial full backup, rendering them less effective.
• Since they depend on the original full backup, if any of the subsequent differential backups fail, the data recovery process might be compromised.

What is the difference between full and differential backup?

The differences between these two types of data backups are quite simple: a differential backup relies on a full backup, while a full backup does not depend on a differential backup.

In simple terms, a full backup means that a copy of the company’s entire data assets is created in one backup file.

On the other hand, a differential backup copies only the files that have changed or been created since the last full backup.

Why don’t businesses create regular full backups?

There’s no doubt that a full backup is the most straightforward form of backup, and it likely provides a higher level of security for your data since all the data is stored in just one file, making it much easier to monitor.

But in today’s world, “easier to monitor” isn’t the only consideration for companies when deciding how to handle their backups.

If an organization performed a full backup every day, it would be expensive, time-consuming, and take up a lot of storage space.

This is where incremental and differential backups come in.

What is the difference between incremental and differential backup?

Incremental backups are very similar to differential backups, but there is one key difference.

As we’ve mentioned, differential backups contain the changes made since the previous full backup. With an incremental backup, each backup contains only the changes made since the last backup—whether that was a full backup or differential.

Because incremental backups may copy fewer files than a differential backup, they typically take up less storage space.

Conclusion

Differential backups strike a balance between efficiency and data security, offering a practical solution for businesses looking to save both time and storage space. While they may not provide the full coverage of a complete backup, they are an essential tool in modern backup strategies, especially when paired with full and incremental backups. By understanding how differential backups work and their advantages, companies can implement more efficient data protection measures, ensuring smoother and faster data recovery when needed. For businesses seeking to optimize their backup process, differential backups offer a smart and reliable option.