US Patent 7644136 Virtual file system

A virtual file system including multiple storage processor nodes including a management node, a backbone switch, a disk drive array, and a virtual file manager executing on the management node. The backbone switch enables communication between the storage processor nodes. The disk drive array is coupled to and distributed across the storage processor nodes and stores multiple titles. Each title is divided into data subchunks which are distributed across the disk drive array in which each subchunk is stored on a disk drive of the disk drive array. The virtual file manager manages storage and access of each subchunk, and manages multiple directory entries including a directory entry for each title. Each directory entry is a list of subchunk location entries in which each subchunk location entry includes a storage processor node identifier, a disk drive identifier, and a logical address for locating and accessing each subchunk of each title.