Patent ID: 8090917

Claim:
A computer-implemented method of managing storage and migration of backup data, said method comprising: receiving, by a virtual tape library (VTL) controller included in a VTL, and via an execution of a first software method and in response to a receipt of a request from a client computing system for a backup of a set of data to generate backup data, metadata that distinguishes among a plurality of different versions of said backup data, wherein said VTL includes a first storage medium and a second storage medium, wherein said metadata includes a type of said backup of said set of data, and wherein said type of said backup is a full backup that is a backup of all data of said set of data, a differential backup that is a cumulative backup of data of said set of data that changes since a latest full backup, or an incremental backup that is a backup of data of said set of data that changes since a latest backup of any type; determining, by said VTL controller, a latest version of said backup data, wherein said latest version is included in said plurality of different versions of said backup data; based on said type of said backup included in said received metadata, determining, by said VTL controller, a migration set of zero or more virtual tapes of a plurality of virtual tapes of said VTL, wherein said migration set is selected from the group consisting of a set of one or more virtual tapes of said plurality of virtual tapes and an empty set including no virtual tape of said plurality of virtual tapes; determining, by said VTL controller and subsequent to said determining said latest version, a storage of said latest version in said first storage medium included in said VTL is complete; and migrating, by said VTL controller and subsequent to said determining said migration set, one or more versions of said backup data from said first storage medium included in said VTL to said second storage medium included in said VTL by migrating said migration set from said first storage medium included in said VTL to said second storage medium included in said VTL if said migration set is said set of one or more virtual tapes, so that said first storage medium retains said storage of said latest version of said backup data and said second storage medium includes at least one version of said backup data that is not said latest version of said backup data.