International Business Machines Corporation

Horace T Tang

Warren B Harding

Connie M Clark

Michelle K Blount

A method for managing data in a data storage hierarchy, and a data storage hierarchy suitable therefor, is disclosed. The data storage hierarchy includes an optical library and separate manually operated shelf storage. The optical library includes at least one optical disk drive and a plurality of storage cells for the storage of optical disks. The optical library also includes automatic means for transferring optical disks from the storage cells to the optical disk drives in the library. The host processor, upon determining that particular data is required to be stored in the optical library, first checks to determine if the optical disks in the optical library currently have the capacity for the storage of such data. If the capacity exists in the optical library there is no problem and the data is stored therein. If the optical library does not have the required capacity, or if the system operator so requires, the optical disk in the optical library which has least recently been mounted on an optical disk drive therein is destaged from the optical library to the manually operated shelf storage. Another disk may then be fed into the optical library for the storage of the data required therein.

Method of managing data in a data storage hierarchy and a data storage

Image data objects are accumulated in a relatively rapid access data buffer, such as a combination of main memory and a rapid access magnetic DASD. An optical disk recorder having a record medium with a plurality of addressable sectors each capable of storing a predetermined number of the VTOC entries receives the accumulated data objects along with the associated VTOC entries in a single access whenever the number of accumulated data objects is an inegral number of said predetermined number. A lower threshold for a minimal number of data bytes of the accumulated data objects may be required before such single access data recording operation is effected. An upper threshold of number of data bytes in the accumulated objects is also provided for causing the single access data transfer irrespective of the number of objects being an integral number of said predetermined number. The invention is advantageously practiced with a write-once, read-many record medium.

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Tucson, AZ, United States of America

Horace T Tang