An airgap is one of the most effective security measures for hacker-proof backup. Implementing an air-gapped backup in your data infrastructure helps improve a disaster-recovery plan. For business continuity, it is vital to have an air-gapped offline backup in case of an emergency, due to ransomware or physical disasters, to get back up and running in no time.

What exactly is an airgap?
The term airgap literally means “gap of air,” so there is a physical separation between the network and the backup. The backup is completely separate from all networks and cannot be accessed at any time when it is removed from the system.

Air-gapped backup is often compared to tapes. Physical tapes can be stored offline and are thus air-gapped by nature, as they are not connected to the network when not in active use. However, tapes are being used less and less these days, but there is a visible shift to hard disks. Thus, since hard disks are not air-gapped by nature, it is even more important to implement an air-gap.

A virtual airgap?
People often talk about a virtual airgap, but does it exist at all? In a virtual airgap, the primary recovery point server (RPS) is replicated to a secondary, remotely managed RPS to create a network separation. This network separation is called the virtual airgap. The airgap is created by using a secure connection between the primary and secondary RPS via a regular, non-administrator account and data transfer via block-based replication.

Virtual Airgap: Contradictio in Terminis
Although a virtual airgap uses a secure connection, the backup is not separate from the network. This is the most important condition of an air-gapped backup! Thus, one cannot talk about an airgap because there is a connection between the backup and a network at all times.

This is an important point that many companies and organizations overlook when deciding to implement air-gapped backup. It is important to create awareness of the difference between an actual air-gapped backup and one based on network separation (virtual air-gap). Companies and organizations need to be able to make the best fit choice when renewing their data infrastructure based on the right objective information.