There are three primary data backup methods – full, incremental, and differential backup. Before you choose the most optimal data backup strategy for your company's needs and preferences, it's important to know the advantages and disadvantages of every backup approach.
A full data backup creates a complete copy of all the data on a device or system, including files, documents, folders, operating system configurations, applications, calendars, and more, regardless of any previously created backups or circumstances.
The entire data copy is backed up and transferred to secure storage – on-site (local storage), off-site (remote storage), or the cloud. Full backups take longer to complete but are most convenient for disaster recovery as they contain the entire data set of the target environment.
Full backups usually provide the most comprehensive critical data loss protection but must be conducted regularly on a carefully defined schedule to optimize time and resource expenditure. Nonetheless, every backup strategy relies on at least one initially created full backup. Afterward, you can combine weekly or monthly full backups with incremental or differential backups.
While full backups are typically easiest to perform, there are several disadvantages to them to keep in mind.
First, full backups use the most storage space compared to the other two methods; if you rely on physical storage, you may need additional hardware to store entire data sets in secure backup. Secondly, full backups require significant network bandwidth and considerable implementation time, depending on the scale and preferences of your business.
The other two approaches – incremental and differential backups – are partial data backups reliant on at least one full backup in storage. They are similar but have one considerable difference.
Incremental backups require users to create at least one full backup beforehand. Then, subsequent incremental backups will store only changed data since the last full or incremental backup.
Since incremental backups only store alterations (changes) to already backed-up data, they require the least storage space. This enables increased backup speeds and requires fewer resources to complete the backup. Nonetheless, incremental backups take the longest to restore. If an organization needs to restore its entire system backup, responsible teams must first recover the target full backup, followed by all incremental backups in order.
If one or more incremental backups are damaged, corrupted, or lost, the disaster recovery process becomes significantly more complicated (or even impossible).
Similar to incremental, differential backup also requires at least one full backup created beforehand. Then, a company can initiate differential backups to include all changed data (files, folders, apps) since the last full backup. As differential backups are cumulative, a combination of full and differential backups includes all files in the company data set (both changed and unchanged data).
Differential backups require more network bandwidth and storage space than incremental backups as they comprise more significant data volumes. However, they enable faster restoration times. A company would only need the initial full backup and the last differential backup to recover its entire system.