The software architecture of a SAN storage control system

We describe an architecture of an enterprise-level storage control system that addresses the issues of storage management for storage area network (SAN)-attached block devices in a heterogeneous open systems environment. The storage control system, also referred to as the “storage virtualization engine,” is built on a cluster of Linux®-based servers, which provides redundancy, modularity, and scalability. We discuss the software architecture of the storage control system and describe its major components: the cluster operating environment, the distributed I/O facilities, the buffer management component, and the hierarchical object pools for managing memory resources. We also describe some preliminary results that indicate the system will achieve its goals of improving the utilization of storage resources, providing a platform for advanced storage functions, using off-the-shelf hardware components and a standard operating system, and facilitating upgrades to new generations of hardware, different hardware platforms, and new storage functions.