The Optical File Cabinet: a random-access file system for write-once optical disks

The Optical File Cabinet (OFC) is patterned after a conventional office file cabinet where all versions of a stored item are retained, but the current version of each item is the easiest to find. The OFC retains the favorable aspects of write-once optical disks while preserving the existing relationship between the operating system and the file system. Alternate approaches to write-once storage and the characteristics of write-once optical disks are described. The salient features of the OFC are examined, namely, the file system tree, growing data structures, and the large memory requirement. The relationship between the OFC and the operating system is discussed. Also considered are reliability, the user-level software interface, long-term storage, simulating the OFC, and implementation of the OFC on a Tektronix 4404 engineering workstation.>