The History of Linear Tape-Open (LTO) Technology.
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Linear Tape-Open (or LTO) is a magnetic tape data storage technology originally developed in the late 1990s as an open standards alternative to the proprietary magnetic tape formats that were available at the time. Seagate, Hewlett-Packard, and IBM originated the LTO Consortium, which organizes development and oversees licensing and certification of tapes and backup device manufacturers.
The standard form-factor of LTO technology is known as Ultrium, the original version of which was brought out in 2000 and could hold 100 GB of data in a single tape. The most recent version was released in 2010 and can backup 1.5 TB in the same size cartridge. Since 2002, LTO has been the best selling high end tape format and is widely used with corporate systems.
LTO History
1/2″ magnetic tape has been used for data storage for more than 50 years. About 30 years ago, IBM and DEC put this kind of tape into a single reel, enclosed media cartridge. IBM called their cartridge 3480 and DEC originally called theirs CompacTape, but later it was renamed DLT and sold to Quantum. In the late 1990s, Quantum’s DLT and Sony’s Advanced Intelligent Tape (AIT) were the leading choices for high-capacity, high speed tape storage for PC servers and UNIX systems. Those formats arehave been tightly controlled by their proprietors. Because of that, their availability was fairly restricted and prices were comparatively high.
IBM, HP and Seagate attempted to counter this by launching a more open format. Around the time of the release of LTO-1, Seagate’s magnetic tape division was spun off as Seagate Removable Storage Solutions, later renamed Certance which, soon after, was acquired by Quantum Corp.
LTO technology was created to be available in two designs, Ultrium and Accelis. For the last few years the LTO format has been very popular, and there are no commercially available LTO Accelis drives or consumables. In common usage, LTO generally refers only to the Ultrium form factor.
LTO Ultrium was created as a pretty much drop-in replacement for DLT. This made it simple for robotic tape library vendors to convert their DLT libraries into LTO libraries.
An Ultrium drive is expected to write data to a tape cartridge in its own generation and to a media cartridge from the immediate prior generation in the prior generation format.
Current LTO Generations
LTO-1 100GB (200GB Compressed)
LTO-2 200GB
LTO-3 400GB
LTO-4 800GB (1.6TB)
LTO-5 1.5TB
The media cartridges last between 15 to 30 years for archival purposes, and can be used for approximately 260 full file passes.
The Linear Tape File System (LTFS) is a self-describing tape format and file system, which uses an XML architecture for ease of understanding & use.
It allows: Files and directories to appear on desktop and directory listings, Supports data exchange
With LTFS tape media can be used the same as other removable media. It was first introduced with IBM LTO Gen5 hardware
WORM
Write Once Read Many (WORM) capability was introduced with LTO Generation 3 tapes. This is normally only used where there are legal requirements such as in banks. An LTO-3 (and later) drives will not erase or overwrite information on a WORM media cartridge, but will read it. A WORM cartridge is identical to a normal tape except its LTO-CM chip identifies it to the drive as WORM and the servo track is slightly different to allow verification that data has not been modified, and may come with tamper proof screws. WORM capable drives instantly spot WORM cartridges and include a unique WORM ID with every dataset written to the tape. There is nothing different about the tape medium in a WORM media cartridge. Typically the WORM cartridges have a different colour packaging.
Although keeping a tape drive clean is useful, the cleaning cartridges are abrasive and regular use will shorten the drive’s lifespan. HP LTO Gen 2,3,4 using a Universal Cleaning media cartridge will always clean when a cleaning tape is inserted, irrespective of whether the drive requires cleaning or not.
The LTO-4 spec added a feature to allow LTO-4 drives to encrypt data before it is saved to tape. All LTO-4 drives must be aware of encrypted tapes, but are not required to actually support the encryption process. The algorithm used by LTO-4 is AES-GCM. The same encryption key is used to encrypt and decrypt data, and the algorithm can detect tampering with the data.
