Looking for additional SIS info? Check out this SIS Whitepaper. This white paper describes the basic architecture of the Single Instance Storage (SIS) feature of the Microsoft® Windows® Storage Server 2003 R2 operating system. This feature helps organizations reduce storage needs for file servers by identifying duplicate files within hard disk volumes and providing an efficient mechanism for consolidating them. The paper also examines the benefits of using SIS, based upon deployment by the Microsoft Information Technology (Microsoft IT) group for Microsoft branch offices and data-center servers. The paper closes with a collection of best practices.