The number of storage subsystems deployed on the data centre has been increasing continually. These systems consist of heterogeneous storage nodes of diverse architectures and storage quality of service (QoS). Meanwhile, various application requirements with different QoS aspirations have been forced to share the data centre. Virtualization of storage helps achieve location independence by abstracting the physical location of the data. This paper presents an ontology-driven model for virtual storage system, and shows how a Publisher Module identifies ontology repository and a Subscriber Module specifies a statement in requesters. Using a Matchmaker Module, we find it allows service providers to differentiate QoS offered to their customers.