Cisco Systems and IBM combine the MDS 9000 Caching Services Module with the IBM TotalStorage SAN Volume Controller Storage Software to form a solution that reduces the complexity and costs of managing SAN-based storage. This solution can create a single pool of storage from disparate storage devices to increase capacity utilization, is simpler to manage and can help lower overall storage costs. By implementing a cache-based, clustered architecture, this solution is highly available and provides the scalability and performance necessary in today's demanding storage environments.Combining the SAN Volume Controller Storage Software with the Cisco MDS 9000 Series Caching Services Module provides a space efficient solution that delivers the benefits of virtualization: managing the combined storage volumes from a central point, implementing copy services from a single license across multiple storage devices, increasing capacity utilization, and avoiding downtime for planned outages. This solution is delivered as a feature of the Cisco MDS 9000 switch, and runs on a clustered pair of Caching Services Modules across switches. Since the solution is achieved in a switch, no additional fabric ports or cables are required. Based on virtualization technology, this solution helps to support a virtualized pool of storage from the storage subsystems attached to a storage area network (SAN). This storage pool helps customers tap into their unused storage capacity and make their business more efficient and resilient. It is an integrated solution supporting high performance and continuous availability in open-systems environments. Storage volumes are represented to applications as virtual disks, created from the pool of managed disks residing behind the Caching Services Modules. Storage administrators can scale performance by adding Caching Services Modules and can scale capacity by adding disks to the managed storage pool.