What is Incremental Backup? Definition, Pros, and Cons

What Is Incremental Backup

What is incremental backup? Incremental backup is one of the three types of backup. The incremental backup can backup files, folders, and even external hard drives.

An incremental backup will save the data and files that have changed since the last backup. Regardless of what type of backup you created previously, an incremental backup will record every alteration.

How Incremental Backup Works

Try to understand how incremental backups work with this example:

• Last Sunday: A full backup was created.
• Monday: One file was added today. An incremental backup of Monday should contain this added file only.
• Tuesday: Three files were added today. An incremental backup of Tuesday should contain three newly added files only.
• Wednesday: Five files were added today. An incremental backup of Wednesday should contain five newly added files only.

We offer a 3-minute video detailing three backup methods, with the key points already highlighted.

• 00:24 Two important backup rules
• 00:42 An example to explain the differences
• 02:01 Features of full, incremental, and differential backup
• 02:44 How to create a better backup strategy

Four Types of Incremental Backup

People divide incremental backup into four types. Let's take a brief look at them:

• Synthetic Full Backup: This merges a full backup with incremental ones. To make one, we need the previous full backup plus any following incremental backups.
• Incremental Forever Backup: Initially, just a full backup is made, and then subsequent incremental backups are sent to the central system. When restoration is needed, these increments automatically combine into a single file.
• Enhanced Incremental Backup: This optimizes backup efficiency by handling files that have been moved or renamed.
• Reverse Incremental Backup: The system produces a new copy that joins the last full backup with the most recent incremental backup. It's like a synthetic full backup, but this new copy is created more regularly.

Advantages and Disadvantages of Incremental Backup

The key characteristic of incremental backup is that it doesn't back up duplicate data. There are certain reasons for choosing or not choosing incremental backup.

Pros:

• Incremental backup files are small enough to save your storage space.
• It is fast to create an incremental backup.
• The Incremental backup can record changes and avoid repeat data.

Cons:

• The data may be lost when you create too many incremental backups.
• As time goes by, it is hard to restore the whole data.

Incremental VS Differential VS Full Backup Explained

There are essentially three types of backup methods: Incremental Backup, Full Backup, and Differential Backup. They each have their distinct characteristics, and we can explore them further by comparing them with Incremental Backup.

Full Backup vs Incremental Backup

A full backup is straightforward to comprehend. It refers to creating an exhaustive backup of selected data or files.

A full backup ensures that you obtain every significant file you desire; however, it also has some drawbacks:

• It takes too long to finish creating a full backup.
• Too much space will be taken up if you want to back up the whole disk.
• Too much repeat data will be recorded.

The incremental backup may partially solve these issues. As mentioned, an incremental backup only records changes, meaning there's no repetition, resulting in smaller backup files and less space occupied on the PC. Since the backup files are small, creating an incremental backup won't take much time.

Differential Backup VS Incremental Backup

The definitions of differential backup and incremental backup are similar, and their similarity can lead to confusion.

A differential backup records the changing data as well, but it only backs up the changes made since the last full backup. It is dependent on a full backup. Let's illustrate with an example:

• Last Sunday: You performed a full backup.
• Monday: A file was added. The differential backup from Monday will include this file only.
• Tuesday: Two new files were added. The differential backup from Tuesday will contain these two newly added files and the file added on Monday.
• Wednesday: Three new files were added. The differential backup from Wednesday will include three newly added files, the two files added on Tuesday, and the file added on Monday.

Most incremental backup files are smaller than differential backup files. It is always fast to create an incremental backup. But as time goes by, too many incremental backup files are created, making it hard to restore data.

So incremental backup is actually easy to create but hard to restore.

Summary

Nowadays, it's common to communicate or collaborate with others using computers or mobile phones. Numerous valuable data need to be saved, in case of virus attacks or the blue screen of death incidents.

This page provides comprehensive information on incremental backup. Each backup method has its distinct features, and if you deem it necessary to back up your data using various methods, perhaps a professional backup software can assist you.