What is differential backup? everything you want 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 were 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 is.

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 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 data files that were changed since the previous whole backup was conducted are copied.

By “changed” we mean any data that was either created, updated, or altered at all, even just a little bit.

Differential backups, in order to actually be differential, begin with a full backup, and after it’s concluded, use the original one as a base point from which to compare the initial files to the subsequent backups. When and if files are either created or modified somehow, they are flagged so they can be copied in the next differential backup.

If this sounds confusing, then worry not as it doesn’t have to be! Take this as an example: let’s say a company completes a full backup on Tuesday, so Wednesday’s differential backup will back up all of the data that had been amended or even 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 heaps of time as well as storage space!

Because there will most likely be significantly less changes to the different data files that have been changed or edited than the whole amount of files within a data repository, a differential backup should take much less time to conclude rather than having to perform a full backup.

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

Why do we need differential backup?

The simplest way to answer the question of why we need differential backups is because they can be huge time and storage savers.

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 can, they more than make up for their cons because they are really practical for companies to perform regularly because they take a smaller amount of time and resources to perform.

As such, many companies and managed service providers (MSPs) will often depend on differential backups as an alternative method as a way to restore data while reducing the restoration time.

What are the disadvantages of differential backup?

While the benefits of differential backups are clear, they obviously also have their cons as well.

Some of the disadvantages of them include but are not limited to:

They rely on a previous full backup. Without one, they can not exist.

In the event that too many differential backups are carried out between full backups, the overall data and storage size of the differential backup might actually become greater than that of the initial one, rendering them pointless.

Because they rely on the initial full backup, if any of the ensuing differential backups fail, then that means the data recovery process will be unable to be concluded.

What is the difference between full and differential backup?

The differences between these two different types of data backup are actually quite simple, as a differential backup relies on a full backup, while a full backup does not rely on a differential backup.

In simple terms, a full backup means that a copy of the company’s entire data assets is backed up into one asset backup file.

On the other hand, a differential backup is the backing up of only the files that were changed somehow or even created since the previous 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 because all the data is stored in just one file, making it much easier to monitor.

But in today’s world, “easier to monitor” is not the only consideration by companies on how to conduct their endeavors.

If an organization were to conduct a full backup every day, that would be really expensive, time consuming, and also take up a lot of storage space.

Enter: incremental and differential backups.

What is the difference between incremental and differential backup?

Incremental backups are very similar to differential backups, but there is a major difference between the two.

As we’ve previously covered, differential backups contain the changes that were made since the previous full backup. Meanwhile, with an incremental backup, each ensuing backup contains only the adjustments that have been made since the previous backup, whether that backup was a full backup or differential.

So, because incremental backups may copy less files than a differential backup would, they therefore can also take up less storage space because of it.