1. A controller for controlling access to media libraries, said controller comprising: a host interface to connect to one or more hosts via a transport medium; one or more storage interfaces to connect to a plurality of physically separate media libraries over one or more additional transport mediums; a computer processor; a computer memory coupled to the computer processor, the computer memory storing a set of computer instructions executable by the computer processor to: associate hosts with virtual media libraries that map to media library components at physically separate media libraries; receive a command from the host, wherein the command references a first virtual media slot and a first virtual drive of a first virtual media library, wherein the first virtual media slot maps to a first physical media slot at first physical media library and the first virtual drive maps to a first physical drive at a second physical media library that is physically separate from the first physical media library such that media cannot be automatically passed between the first physical media library and the second physical media library; and forward the command to the first physical media library, wherein the forwarded command references the first physical media slot and a second physical drive at the first physical media library to redirect the command from the first physical drive to the second physical drive.