1. A method, performed by at least one computing device having a processor and memory, for calculating data availability in a computer network, the method comprising: identifying, by the computing system, multiple data storage elements in the network, wherein the multiple data storage elements include primary data storage elements and secondary data storage elements, and wherein the primary data storage elements include disk-based data storage media, and wherein the secondary data storage elements include tape-based data storage media; accessing, by the computing system, storage availability data associated with the multiple data storage elements; and calculating, by the computing system, a storage availability level for the multiple data storage elements based on the associated storage availability data, wherein the storage availability level indicates a rate at which data can be written to the primary and secondary storage elements or a rate at which data can be retrieved from the primary and secondary data storage elements.