International Business Machines Corporation

Harrison L Freeman

Richard G Mustain

Thomas Marshall Hoag

William Jaaskelainen

Carol A Peters

Larry D Shumway

A directory structure for WORM optical media which supports a multi-level tree structure containing several paths is disclosed. When a user defines the first path on the WORM volume, a file directory group is created for that path. A path directory entry pointing to this file directory group is written to the path directory group. Files having this path name are initially written into the first data file area next to this file directory group. The first data file area grows as data is written into it. When a second path is defined, the first data file area is closed and a second file directory group is created on the WORM volume next to the first data file area, thereby wasting little if any space. The path directory group is updated with a new path directory entry that points to this new file directory group. Files having this second path name are written into a growing second data area. If the user now wants a file having the first path name to be written to the disk, a file directory entry is placed in the first file directory group, but the file itself is written into the growing second data file area. In this manner, files are associated with directory entries by a common path name, not necessarily physical location on the disk, although files tend to be relatively close to their associated directory entry.

Directory structure for worm optical media

A computer system and method for efficiently managing Write Once Read Mostly (WORM) volumes on mass optical storage devices are disclosed. A configuration menu asks the user to enter a threshold percentage from 1-100%. The threshold percentage is multiplied by the volume size to determine a threshold block address. New files are written sequentially to the WORM volume up to but not exceeding the threshold block address, unless a threshold override indicator is enabled. Space on the WORM volume between the threshold block address and the end of the WORM volume is reserved for updated files. Updated files can be stored anywhere on the WORM volume, including above the threshold block address. Reserving space for updated files on a WORM volume allows more updated files to be stored on the same WORM volume as original files, and reduces the number of optical disks required to be read. The threshold percentage can be modified by the user at any time desired

System and method for worm volume management of new and updated data

A method of and apparatus for automatically assigning a name to a storage file. This assignment technique is particularly pertinent to storage files used in conjunction with an optical storage system. The automatically assigned name is used throughout the system to identify the storage file for all purposes including loading and unloading the storage file to and from the various drives within the system, initializing the storage file for use, and reading and writing to and from the storage file. Automatic name assignment normally occurs when a storage file is placed within a mass storage library. A name becomes necessary at that time because the storage file is then available to the system. Alternate automatic name assignment also occurs when for any reason the system is unable to read the name written on a storage file. The automatically asigned name may be replaced with a user supplied name upon operator request.

Growing community of inventors

Kasson, MN, United States of America

Harrison L Freeman