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Managing Optical Media As an On-Line Archive

IP.com Disclosure Number: IPCOM000037292D
Original Publication Date: 1989-Dec-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Jaaskelainen, W: AUTHOR [+3]

Abstract

An "on-line archive" method of support for a mass optical storage device (MOSD) provides direct access to data by applications or users without operator intervention. In addition, a same optical platter may be removed from one MOSD and entered into a different MOSD attached to another system with the new system having a same direct access to data.

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Managing Optical Media As an On-Line Archive

An "on-line archive" method of support for a mass optical storage device (MOSD) provides direct access to data by applications or users without operator intervention. In addition, a same optical platter may be removed from one MOSD and entered into a different MOSD attached to another system with the new system having a same direct access to data.

The direct access of data is provided by mapping requests for optical data to a staging manager. The staging manager copies the data between system direct access storage devices (DASDs) and optical disk. The data itself are preserved on optical disk in an 'interchange format'. The data are restored to the system internal format each time they are copied from optical disk.

The process of copying the data is done at open time for reads and close time for writes. Operator intervention is avoided by intercepting all open and close requests and automatically staging the data to DASD and back to the optical disk as required. This also allows all user or application gets and puts to operate on the data while they are on DASD where accesses are significantly faster. This approach also frees up the optical drive that reads and writes the data much quicker since the data are copied to DASD using large block sizes, and the device is only allocated for the length of the copy.

The capability to move an optical platter to a different MOSD is accomplished using two techniques. First the dat...