A high-capacity data storage system for storing, retrieving, reading and writing multiple magnetic tape cartridges. Also called a "tape automation system," it contains storage racks for holding the cartridges and a robotic mechanism for moving the cartridge to the drive.
Tape libraries were made for almost every size and type of magnetic tape cartridge, but only the larger ones survived. Small libraries had a handful of drives and held up to several hundred cartridges. Large units support dozens of drives and thousands of cartridges.
Accessing data in a tape library takes from a few seconds to a minute or more in order to retrieve and load the cartridge into the drive and locate the data on the tape. See cartridge
and magnetic tape
A Large Tape Library
Years ago, StorageTek's RedWood SD-3 was one of the largest tape libraries, holding up to 6,000 helical scan cartridges for a total of 300 terabytes. Subsequent StorageTek units have capacities up to 50 petabytes. (Image courtesy of Storage Technology Corporation.)
All tape and disk libraries have a robotic-like device that retracts and inserts the cartridges and moves them to the read/write heads. This photo shows the mechanism in an AIT library from Cambridge Computer Services, Inc. The tapes are held in a rotating carousel (left) that can hold hundreds of cartridges.