Archiving online data to optical disk
Janet Porter, James L. Kiesler, D.A. Stedfast · Antarctica A Keystone in a Changing World · 1990
The U.S. Geological Survey has stored instantaneous values of hydrologic data (unit values) on minicomputers since 1985.A substantial amount of disk storage is required for the online storage of these data.Traditionally, these data have been archived on magnetic tape to make disk storage space available for additional data.However, magnetic tapes have a limited shelf life, and retrieval of data for a specific site is cumbersome.As the volume of unit-value data to be archived has expanded, the need for a more efficient method for data storage and retrieval has increased.The U.S. Geological Survey's Distributed Information System Program Office is currently (1990) assessing optical disk storage as an alternative means of archiving unit-value data.Optical disks have a longer shelf life than magnetic tapes, and retrieval of archived data is substantially easier.The cost for data storage on writeonce/read-many optical disks is comparable to that of magnetic tape and only a fraction of the cost for fixed magnetic disk (hard disk) data storage.In a test study, unit-value data was archived using one optical disk drive connected to a microcomputer and a second drive connected to a minicomputer.The cost of data storage, alternative forms of data storage, and specifications for data retrieval are described.