Methods, systems, and computer-readable media with executable instructions stored thereon for backup storage management are provided. A utilization threshold can be defined for each of a number of virtual tape libraries (VTLs). A number of slipped backup jobs can be identified, wherein each of the number of slipped backup jobs is associated with one of the number of VTLs. A number of storage statistics for each of the number of VTLs can be collected and storage can be allocated for each of the number of slipped backup jobs via a VTL backup storage manager that analyzes the utilization threshold, the number of slipped backup jobs, and the number of storage statistics for each of the number of VTLs.