What is Incremental Backup? A Complete Guide to Data Protection

Backing up your data is the most important thing you can do to safeguard your files and settings. Only through a robust backup strategy can you ensure business continuity in the event of disruption, such as from hardware failure, accidental deletion, or ransomware.

Incremental backup is one of several methods organisations can use to protect their data. But what does incremental backup mean and what are its advantages compared to the other backup solutions?

What is incremental backup?

As the name suggests, incremental backup involves backing up your data in increments. Rather than creating a replica of all your files, an incremental backup will only record any changes made since you performed your last backup.

Incremental backup is therefore different to performing a full backup, which creates a complete copy of all your data no matter what has or hasn’t changed within individual files.

Here’s an example of how that might work in practice:

• On Sunday, you perform a full backup, capturing all of your data.
• On Monday, you run an incremental backup, storing only the changes made since Sunday.
• On Tuesday, you perform another incremental backup, capturing any changes made since Monday’s incremental backup.

If you were to lose your data on Wednesday, your first step would be to restore Sunday’s full backup. You would then recover Monday and Tuesday’s incremental backups individually to restore your files to their most recent versions.

Incremental backup vs. differential backup

In addition to full backup and incremental backup, there’s also a third option for protecting your data: differential backup. When you create a differential backup, you save any changes made since the last full backup. This may sound similar to running an incremental backup, but there’s a subtle distinction.

A differential backup will always use the latest full backup as its starting point, capturing any changes made to that version of the data. By contrast, an incremental backup can build off any type of backup, be it full, differential, or a previous incremental backup.

The easiest way to understand this is the number of files required to recover your data. Using the previous example, you would need three files: Sunday’s full backup plus Monday and Tuesday’s incremental backups. With differential backup, you only ever need a maximum of two files: the latest full backup and the latest differential backup.

Advantages of incremental backup

Given the above, you may be wondering why a business would ever choose incremental backup over differential backup. There are several reasons why incremental backup may better suit your needs:

1. Efficient storage use: By only storing new or modified data, incremental backups use less storage than either full or differential backups.
2. Cost-effectiveness: For organisations with large and frequently changing datasets, incremental backups can considerably reduce storage costs.
3. Faster backup times: By only capturing the most recent set of changes, you can back up your data a lot faster than by running a full or differential backup.
4. Lower system load: Incremental backups consume fewer computing resources, which helps to reduce the impact on system performance during the backup process.

Incremental backup vs. differential backup vs. full backup

Each backup method has its own set of advantages and disadvantages. Choosing the best option comes down to how you prioritise storage use, backup speed, and recovery time.

Incremental backup uses the least amount of data and has the fastest upload times of any of the three options. However, it also has the slowest restoration process and requires careful management by IT teams given the potentially large number of files involved in the recovery chain.

When to use incremental backup

Incremental backup provides the best solution for many organisations:

• Frequently changing data: If you need to perform backups daily or even hourly, incremental backup is the most agile option.
• Storage optimisation: Businesses looking to keep their storage costs to a minimum use incremental backup to avoid duplicating unchanged data.
• Hybrid strategies: You don’t have to pick just one type of backup method. Many companies combine full, differential, and incremental backups to provide the most efficient recovery options.

How to use incremental backup

If you decide to use incremental backup to protect your data, there are several best practices to follow:

• Automate backup schedules: Using backup software to run regular incremental backups will protect your data without you having to lift a finger.
• Combine with other backups: Periodically performing a full backup or differential backup will avoid an unruly build-up of incremental backups.
• Test your recovery process: Regularly verifying the integrity of your backups will prevent any nasty surprises when you come to recover your files.
• Use offsite or cloud storage: Storing your copies securely in the cloud protects your backups from local failures or physical threats.

Conclusion

Incremental backup provides the fastest route to safeguarding your data at the lowest possible cost. However, while these factors may seem appealing when it comes to protecting your data, restoring your files from incremental backups is the slowest and most complicated process.

If you need frequent backups and cost-effective storage, incremental backup provides a vital lifeline. Balancing the use of incremental backups with regular full or differential backups can ensure you benefit from the advantages of each option.