Incremental and Differential

As time progresses, there will be more and more data and files stored on your system drive, data partitions, etc. In order to ensure data integrity, it is important to back up changed data regularly.

There are 3 options available: Full, Incremental and Differential Backup. The following paragraphs describe the differences, and can help you decide your backup plan:

Backup

Tips: For a step-by-step guide with screenshots displaying how to perform an Incremental or Differential backup, please click here: How to Do Incremental and Differential Backup.

Full Backup

A full back up takes a snapshot of all the data on the selected folders, partitions or hard disks at the time the backup is performed, and saves it to an Image file. A full backup is always the basis of any incremental and differential backup. A Full Backup can be used to restore all the files and folders in its image, to the state when the image was created.

Once you have performed a Full backup, you can create Incremental and Differential backups. These are much quicker to create than a Full backup of the same data and the images created are smaller

Full Backup

Incremental Backup

An Incremental backup takes a snapshot only of the changed and newly added files based on the previous related backup, be it a full or incremental backup. Data that have not changed will not be backed up. A Full Backup must exist as the start point of a series of incremental backups. A typical set would be, in time sequence:

Full Backup, as basis
Incremental Backup 1
Incremental Backup 2
…..
Incremental Backup n

All the image files of incremental backup series share a sequential relationship.

All data can be recovered to the state when any Incremental Backup was done, by recovering the parent Full Backup, followed in turn by each Incremental Backup in between.

If any one of the incremental image files in the sequence is damaged or missing, subsequent image files will be invalid.

"Full Backup + regular Incremental Backup" is the most commonly-used backup scenario.

Incremental Backup

Differential Backup

A Differential Backup is always directly related to its originating Full Backup. It will back up all data added and changed since the Full backup was done. If one of the differential backup image file becomes damaged or lost, it will not affect others.

All data can be returned to the state when the Differential Backup was done, by recovering the parent Full Backup, followed by the required Differential Backup. As time progresses, each Differential Backup will become progressively larger, because each will contain more changes made since the Full Backup was done.

Compared to Incremental back up, Differential back up can cost more time and disk space.

Differential Backup

Full Backup + Incremental or Differential

With the demonstrations above, you might have found out that the method of "Full Backup + Incremental Backup" or "Full Backup + Differential Backup" will be more convenient than single full backup. Therefore, after a full backup, you can choose whether incremental or differential backup to only deal with the changed and newly added data and files. It will be more efficient.

What's more, the way of "Full Backup +Incremental Backup" has been employed more frequently than other approaches. It will only deal with the changed files since the last backup. Therefore, if you need to back up data regularly, this way will be more appreciated and time saving. The way of "Full Backup + Differential Backup" is also a good solution. However, compared to incremental backup, it will cost more time and also it needs more space to store the image file.