Incremental cloud backup

An incremental backup is a basic technique for securely archiving data and files. Users often compare the full backup to the incremental backup to contrast the typical method as an alternative.

An incremental backup process compares current data against a prior full backup. If an incremental backup is taken before a full backup is performed, the backup system forces a full backup instead. A full backup covers all folders and files throughout a system. No new information is lost if full and incremental backup methods are correctly combined over time. A complete restore from such a system requires restoring the full backup followed by restoring the data found in each incremental backup.

A related concept is a differential backup that backs up any data that has changed since the last full backup rather than the last incremental backup. Differential backups may be combined with incremental backups. For example, a company might perform a monthly full backup, followed by weekly differential backups and daily incremental backups. A complete restore from such a system would require restoring the latest full backup and the latest differential backup followed by any incremental backup since the latest differential backup.

Full backups, differential backups, and incremental backups are all fairly typical enterprise cloud backup methods. Less common types include incremental-forever backups and synthetic backups. Here is how the common types of backups compare:

Full backups

Full backups represent complete copies of all configured data. It’s essential to have all data entirely backed up, but this backup is best used periodically. Creating full backups can consume too many resources — including time, storage, and network bandwidth — to implement frequently.

Incremental backups

Incremental backups reflect only what has changed in the data since the last backup — whatever type of backup it was. This option consumes less storage space and time, but it also means a more difficult restore process. This is because it essentially means restoring both the last full backup as well as the last incremental backup.

Differential backup (cumulative incremental backup)

A differential backup also focuses solely on changed data. However, the differential backup restores back to the last full backup, where an incremental backup just goes back to the last backup of any type.

Comparing incremental vs. differential vs. full backups, an incremental backup includes only the most recent changes from the last backup of any kind. A differential backup goes back to the last full backup.

How full backups are performed, or if they are performed at all, can vary greatly between backup systems. An incremental-forever approach only performs one full backup followed by incremental backups forever. A subset of this type is a block-level incremental-forever backup, which stores all blocks that have changed since the last backup vs. an incremental backup that stores all files that have been created or modified since the last backup.

Full backups can also be created via a mechanism referred to as a synthetic full backup, where a full backup is constructed by copying data from backups that have already been created. A synthetic full backup consumes no resources of the system being backed up; only the backup server and its storage are used.

See the discussion below for more advantages and disadvantages of full vs. incremental vs. differential backups.

Traditional incremental backups and incremental-forever backups are all possible types of incremental backups. They are usually combined with a periodic full backup or a synthetic full backup.

Incremental-forever backup

Just like a standard incremental backup, an incremental-forever backup begins with a full backup; however, from that point forward, the system only conducts incremental backups with no periodic full backups at all. After enough time, full restoration is possible with reorganized stored data from all backups.

Incremental-forever backup advantages

Advantages of an incremental-forever backup strategy include fast incremental backup and a quicker ability to restore operations during critical times. Advantages also include low requirements for storage space and reduced demands on the network.

Synthetic full backup

A traditional full backup backs up all data from the original system being backed up. A synthetic full backup does not use the original system to create a new full backup.

Instead of performing another full backup from the original system, the system consolidates its incremental backups to synthesize a new “full backup.” This is the new starting point, and incremental backups continue from that point.

Synthetic full backup advantages

Advantages of a synthetic full backup include faster backups and a reduced load on the backed-up system such as the backup client. A synthetic full backup also reduces demands on the network.

The primary difference between incremental and differential backup focuses on the source file for backups and when it is consulted.

Both an incremental backup and a differential backup are efficient versioning systems, backing up only data that has changed to save disk space and time. The distinction is which backup they use as a reference point: the last full backup or the last incremental/differential backup.

Even in the industry, these types of backups are often called different things. For example, a differential backup may be referred to as a cumulative incremental backup, whereas an incremental backup might be called a differential incremental backup.

The difference between differential incremental and cumulative incremental backups is less a matter of confusing technical details and more a matter of semantics. It is also the same difference in the source file for the backup reference.

Consider the differences between incremental and differential backups in the following example. Both techniques save disk space and time compared to a full backup by backing up only files and data that have changed. This makes sense because in actuality, most data on any given computer changes infrequently.
Real-world example:
Your team conducts a full backup on Monday. Now you can either conduct differential backups moving forward or incremental backups — or some combined strategy.

If you conduct differential backups, each one will back up everything that has changed since Monday, every single time. So Tuesday’s backup has everything new since Monday, and so does Wednesday’s — even if some of the data didn’t change from Tuesday to Wednesday.

If you conduct incremental backups instead, you will capture only what changed, every time. The result will be smaller capsules of only altered data. It takes less time and burns less storage space, but it can take longer to conduct a complete restore, depending on your backup system. This is why many enterprises use both differential and incremental backups.

Many businesses perform a daily incremental cloud backup as part of their strategy. This lets them capture changed data without incurring excessive costs.

How you create incremental cloud backups will depend in part on your business’ size and the nature of your data. Techniques vary because best practices shift depending on your business and data goals.

For both incremental and differential backups, modern cloud backup and archiving solutions have workflows to take users through the execution process from initial implementation through the final validation of data archives.

What is the practical difference between incremental and differential backups? Primarily speed and cost for both storage and restoration time.

The first incremental backup and differential backup difference is about backup speed. This has to do with how incremental backup works.

The first difference is speed. Since incremental backups are focused on the smallest amount of data, they are the fastest to perform. In fact, they can often be performed hourly or even every minute.

Differential backups are faster than full backups, but the longer it has been since the full backup, the longer they take to conduct. On the other hand, incremental backups are slower in the restoration process.

Restoring incremental backup files can be slower than restoring with other backup methods. Full backups are ready to restore as is, and differential backups take less reconstruction, typically, to build a full dataset.

In fact, in certain situations, the backup software may need all iterations of the incremental backup to restore data. It also won’t be able to restore it should any of the pieces be missing. In such systems, performing an occasional differential backup will help speed up recovery.

A full backup has its advantages: it stores your data completely and you don’t risk losing it. However, full backups take a long time and lots of storage space. In addition, each complete copy of data carries the risk of a breach with it.

Incremental backup addresses these issues. Advantages include requiring far less storage space and faster backup times. By contrast, the disadvantages of incremental backup are the complexity and time-requirements of restoration.

Some modern backup systems, especially cloud-based backup, do not need to perform occasional full backups to speed restore times. They store backup data in object format and restore all data and files simultaneously regardless of how it was backed up.

A reverse incremental backup, like other incremental backups, begins with a full backup. It also shares some qualities of a synthetic full backup.

In a reverse incremental backup process, the system performs incremental backups after a full backup. It then (reversibly) updates the full backup. The result is a synthesized full backup that includes all of the latest data. This updated full backup enables faster restoration, relieving some of the issues presented by incremental backups.

Incremental backup software works by including the functionality to conduct incremental backups in one place. Incremental file backup software can protect your business’s critical data from anything from viruses, errors, and corruption, just like conducting a full backup.

However, it does this as an all-in-one solution. This way you do not have to manage the schedule or strategy manually.

The best backup strategy will be specific to your business. However, in general, the best backup software should be able to perform in a variety of situations.

Strong backup software should use less space by compressing and deduplicating file contents. It should encrypt and protect your data and offer cloud protection with high levels of uptime on dedicated servers. It should allow you to choose different types of backups and customize your backup strategies based on your requirements and goals.

The best backup software offerings also let users restore systems easily and offer support, fixes, and updates. They work on schedule, seamlessly, without intervention from the user, until they are needed in times of crisis.

However, all software has limitations, and there are other backup tools available. A cloud solution, for example, eases disaster recovery when infrastructure is damaged.

Experts recommend a solution that implements more than one of these backup approaches, including a periodic full backup, as part of an overall data-integrity strategy. You should also conduct a full backup anytime you make a major alteration to the system such as installing new software or updating your operating system.

Druva’s flexible enterprise cloud backup solution is built using a cloud-native architecture that enables secure, simple, scalable enterprise cloud backup and restoration, even where bandwidth is scarce.

No hardware or software means there is no hassle in deployment. Cloud backup delivers up to a 50 percent lower TCO. Your organization can accelerate backup and restore performance by consolidating global backups into a single data lake. Plus, simplify disaster recovery, eDiscovery, search and compliance. Ultimately, with Druva’s enterprise cloud backup, your organization will increase the predictability and transparency of costs, improve business resiliency, and enhance financial flexibility.

Discover how Druva helps organizations reduce the cost and complexity of backup operations by eliminating infrastructure and automating critical tasks. Watch the video below to learn more.