Originating Author: David Floyer
Delivery-side storage virtualization stands between the application and the storage. It interprets the application I/O requests for storage, knows where the physical storage is located, and translates the requests. The major benefits of delivery-side virtualization include better utilization of physical resources (data can be spread and shared to optimize space and performance), and better ability to move data to meet service level requirements at minimum cost (e.g., data migrations within tiered storage).
Service-side storage virtualization stands between the administrator and the application. It allows the administrator to name and allocate virtual resources (e.g., virtual volumes). The application thinks that it has access to all the storage, but the service-side virtualization allocates real storage as actually required. The major benefits of service-side virtualization include better utilization of storage resources, greater flexibility to dynamically reallocate storage resources (e.g., to improve performance or lower cost) and better information about storage to the application owners (e.g., about storage resources that could be used, that are actually being consumed and the services levels being delivered).
Action item: Both types of storage virtualization can deliver very significant benefit and together can half the cost of storage and storage management, as well as improve the dialog between application owners and IT. They are basic enablers of a storage services architecture.
