As a general term, open storage refers to storage systems built with an open architecture using industry-standard hardware and open-source software. In an open architecture, customers can select the best hardware and software components to meet their requirements. For example, a customer who needs network file services can use an open storage filer built from a standard x86 server, disk drives, and OpenSolaris technology at a fraction of the cost of a proprietary NAS appliance, such as a NetApp fabric-attached storage (FAS) system. During this decade, open-source software has radically altered the computing landscape. Many new storage systems use Linux or OpenSolaris as their base operating system. Vendors have turned open source into proprietary systems by augmenting basic Linux with their own storage-specific features such as snapshots, remote replication, and volume management. Ironically, most of these systems come to market as closed systems, and customers are not able to add software, substitute disk drives, or modify the vendor’s software.