- Nearline storage
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Nearline storage (where the word "nearline" is a contraction of near-online) is a term used in computer science to describe an intermediate type of data storage that represents a compromise between online storage (supporting frequent, very rapid access to data) and offline storage/archiving (used for backups or long-term storage, with infrequent access to data).[1][2] The nearline storage system knows on which volume (cartridge) the data resides, and usually asks a robot to retrieve it from this physical location (usually: a tape library or optical jukebox) and put it into a tape drive or optical disc drive to enable access by bringing the data it contains online.[3] This process is not instantaneous, but it only requires a few seconds.
Both archiving and nearline allow a reduction of database size that results in improved speed of performance for the online system. However, accessing archived data is more complex and/or slower than is the case with nearline storage, and can also negatively affect the performance of the main database, particularly when the archive data must be reloaded into that database.[4]
In addition, some storage systems vendors and suppliers appear to be using the term in reference to low-rotational speed hard drives. Specifically it is being used to refer to high-capacity Serial ATA drives that work with Serial Attached SCSI storage devices. Presumably this usage is by analogy to the high-capacity and low-access speed tape systems.[5]
References
- ^ "Nearline storage" in "A Glossary of Archival and Records Terminology". Retrieved on 2009-01-30.
- ^ Venkatramani, Chitra and Tzi-cker Chiueh (1993). "Survey of Near-Line Storage Technologies: Devices and Systems". Experimental Computer Systems Laboratory.
- ^ "Near-line storage" in "Webopedia Computer Dictionary". Retrieved on 2009-01-30.
- ^ Ritchie, Arthur (2008), "Nearline and archiving in the data warehouse: what's the difference?". Database and Network Journal, October issue. Retrieved on 2009-01-30.
- ^ Seagate Technology Paper TP-543 (2005), [1]. Retrieved on 2011-06-10.
Categories:- Computer science stubs
- Computer storage
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