Modular data storage directories for large-capacity data storage units

摘要

An updatable and expandable directory structure and resultant access procedures emulating a write-once or indelible record medium (20) to a rewriteable record medium as to accessing characteristics. The directory is indexed; one directory header for a first set of files indexes another set of files. Sector clusters or data extents are managed such that random recording from any file proceeds independently of write-once characteristics. The directory is stored on the medium as data is recorde. Each directory entry contains an archival history of recording of a related data file in the medium. Both logical and physical addressing is employable.