A storage for storing backups of virtual machines includes a persistent storage and a garbage collector. The persistent storage stores the backups. The garbage collector identifies an end of a backup generation session; in response to identifying the end of the backup generation session, the garbage collector performs a date analysis to identify a set of potentially stale backups of the backups; performs a continuity chain analysis of each backup of the set of potentially stale backups to identify a set of stale backups; and deletes each backup of the set of stale backups.