Data Backup Software and Service

As many people pay more and more attention to secure their data, multiple methods to backup appears: Full Backup, Daily backup, Differential backup, Incremental backup, Network Backup, Dump Backup, etc. And this article will give you a brief introduction about differential backup.

Differential backup is a process of backing up only those files that were created or changed since the last full backup. It is a kind of backup that copies all files that have changed since the last full backup. Each differential backup will include all files in previous differential backups since the full backup so to restore a version of a file, you only need to search the full backup and the relevant differential backup.

A differential backup is not as fast as an incremental backup, but it is faster than a full backup. It requires more storage space than an incremental backup, but less than a full backup. In other aspect, a differential backup requires more time to restore than a full backup, not as much time to restore as an incremental backup.

When to Perform Differential backups:
1. A relatively small portion of the data in the database has changed since the last database backup. Differential database backups are most efficient if the same data is modified frequently.

2. You are using the Simple Recovery model, which does not permit Transaction log backups, and you want to perform backups more frequently that are practical for full database backups.

3. You are using the Full or Bulk-Logged Recovery model and want to minimize the time it takes to roll forward Transaction log backups when restoring a database.

As previously mentioned, differential backup shortens restore time compared to an incremental backup. However, if you perform the differential backup too many times, the size of the differential backup might grow to be larger than the baseline full backup. So here is a list about its advantages and disadvantages:

Advantages:

Restore is faster than restoring from incremental backup

Backing up is faster than a full backup

It uses less storage space than full backup

Disadvantages:

Restore is slower than restoring from full backup

Backing up is slower than incremental backup

It uses more storage space than incremental backup

A differential backup provides a backup of files that have changed since a full backup was performed. A differential backup typically saves only the files that are different or new since the last full backup, but this can vary in different backup programs. Together, a full backup and a differential backup include all the files on your computer, changed and unchanged. But it should be performed daily on production systems.