Linear Tape Open (LTO) is, as the name implies, an attempt to develop an open standard for linear tape storage as an alternative to the proprietary Quantum DLT format. Proposed and developed initially by a consortium of Hewlett-Packard, IBM and Seagate, LTO technology combines the advantages of linear multi-channel, bi-directional formats with enhancements in servo technology, data compression, track layout and error correction code to maximise capacity, performance and reliability.
There are two formats based on the LTO technology:
- Accelis: a format designed for applications that require exceptionally fast access times, such as on-line data inquiry and retrieval. Tape devices based on the Accelis format are expected to provide data access in under 10 seconds. The Accelis format is slated to debut with capacities of up to 50GB compressed (25GB native) capacity on a dual-reel cartridge and deliver transfer rates from 20-40MB per second compressed (10 to 20MB per second native). Subsequent capacity and performance advancements are expected to result in products with access times under 7 seconds, capacities of up to 400GB compressed (200GB native) and transfer rates ranging from 160-320MBps compressed (80MBps to 160MBps native)
- Ultrium: a single-reel format targeted at users requiring ultra-high capacity backup, restore and archive capabilities. The Ultrium format enables manufacturers to develop products with up to 200GB of compressed capacity and deliver transfer rates from 20-40MB per second compressed (10 to 20MB per second). When Ultrium products reach the market, a single 200GB drive is expected to be able to accommodate cartridges of varying capacities from 20GB compressed (10GB native) to 200GB compressed (100GB native). Ultimately, compressed capacities are expected to rise to 1.6TB (800GB native) on a single cartridge and transfer rates to between 160-320MBps compressed (80MBps to 160MBps native).