Cloud backup enables tapping into cloud economies of scale, as well as being located off-premises, thus protecting against catastrophic site failures such as fire or flood. In the last 10 years, we have seen a rapid decrease in the use of on-premises backup solutions. Instead, companies are increasingly opting for hybrid backup solutions that combine a local backup vault with a cloud vault. The local vault is used for day-to-day recoveries, while the cloud vault is used for long term and for recovery from rare, yet catastrophic, whole-site failures.