Editing Tape library (section)

=== Design ===

Physically automated tape library devices can store immense amounts of data, ranging from 20 [[terabyte]]s<ref>{{Cite web|url=http://h18006.www1.hp.com/products/storageworks/msl2024/index.html|title=HP StorageWorks MSL2024 Tape Library - overview|date=March 18, 2006|access-date=June 19, 2018|archive-date=March 18, 2006|archive-url=https://web.archive.org/web/20060318182700/http://h18006.www1.hp.com/products/storageworks/msl2024/index.html|url-status=bot: unknown}}</ref> up to 2.1 [[exabyte]]s of data<ref>[[Oracle Corporation|Oracle]] {{cite web|url=http://www.oracle.com/us/products/servers-storage/storage/tape-storage/sl8500-modular-library-system/overview/index.html|title=StorageTek SL8500 Modular Library System}}</ref> as of 2016.  Such capacity is multiple thousand times that of a typical [[hard drive]] and well in excess of what is capable with [[network attached storage]]. Typical entry-level solutions cost around $10,000 USD,<ref>[http://h71016.www7.hp.com/dstore/ctoBases.asp?jumpid=re_NSS_msl2024&ProductLineId=450&FamilyId=2297 HP Small & Medium Business Online Store: HP StorageWorks MSL2024 Tape Libraries]</ref> while high-end solutions can start at as much as $200,000 USD<ref>[http://www.oracle.com/us/products/servers-storage/storage/tape-storage/sl8500-modular-library-system/overview/index.html]. Cites cost as "From $195,830. (US)"</ref> and cost well in excess of $1 million for a fully expanded and configured library.

For large data-storage, they are a cost-effective solution, with cost per gigabyte as low as 2 cents USD.<ref>{{cite web|url=https://www.forbes.com/sites/tomcoughlin/2016/07/24/the-costs-of-storage/#29cedc803239|title=The Costs Of Storage|work=Forbes}}</ref> The tradeoff for their larger capacity is their slower access time, which usually involves mechanical manipulation of tapes.  Access to data in a library takes from several seconds to several minutes.

Because of their slow sequential access and huge capacity, tape libraries are primarily used for [[backup]]s and as the final stage of [[digital archiving]]. A typical application of the latter would be an organization's extensive transaction record for legal or auditing purposes. Another example is [[hierarchical storage management]] (HSM), in which tape library is used to hold rarely used files from [[file system]]s.