Cloud backup is a strategy for copying data to a server at a remote data center so that it will be preserved in case of equipment failure or other catastrophe. The off-site server may be hosted in a proprietary, private cloud or it may hosted by a public cloud service provider who charges the customer a fee for storing and maintaining the backup. Cloud backup is also known as online backup.
Online backup systems in a public cloud typically run on a schedule that is determined by the level of service the customer has purchased. If the customer has contracted for daily backups, for instance, then the application collects, compresses, encrypts and transfers data to the service provider's servers every 24 hours. To reduce the amount of bandwidth consumed and the time it takes to transfer files, the service provider might only provide incremental backups after the initial full backup.
Third-party cloud backups have gained popularity with small offices and home users because the process is convenient. Capital expenditures for additional hardware are not required and backups can be run dark, which means they can be run automatically without manual intervention.
In the enterprise, cloud backup services are primarily being used for archiving non-critical data only. Traditional backup is a better solution for critical data that requires a short recovery time objective (RTO) because there are physical limits for how much data can be moved in a given amount of time over a network. When a large amount of data needs to be recovered, it may need to be shipped on tape or some other portable storage media.