Is LTO-5 the last hurrah for tape?

Imation to make 1.6TB LTO-5, but is it tape's last stand?

Imation will soon be making the industry's first terabyte-plus raw capacity tape, in the LTO-5 format, with delivery in early 2010.

The Linear Tape Open (LTO) consortium has three technology-providing members: HP, IBM and Quantum. It defines tape formats against which the three members build drives and independent licensed manufacturers manufacture tape media and build drives. The current format is LTO-4, with a raw capacity of 800GB.

The LTO development roadmap has LTO-5 as its next format and this is what Imation is now licensed to manufacture. Its raw capacity is twice LTO-4's, 1.6TB, with a 2:1 compressed capacity of 3.2TB. LTO-3, the prior generation and format to LTO-4, had a capacity of 400GB raw and and an 80MB/sec transfer speed. The transfer speed rose to 120MB/sec with LTO-4 and will rise again to 180MB/sec with LTO-5.

The LTO website above quotes such figures in compressed data form and so says LTO-5 capacity and transfer rates are 3.2TB and 360MB/sec respectively.

Imation expects to deliver LTO-5 tape media in early 2010 and will, logically, have been developing the media using pre-production versions of LTO-5 drives. These drives will support WORM (Write Once Read Many) format for archiving of unalterable data on tape, and also encryption to secure the contents against unauthorised access. They will also probably support the reading of LTO-4 format tapes and so provide an upgrade path to LTO-4 users needing more capacity.

So far the three technology providers are not saying anything about LTO-5 drives, and nor are other LTO-licensed drive manufacturers such as Tandberg.

Mainframe tape drive and media users have access to 1TB tapes from IBM, 3592 media with the TS1130 drive, and Sun/StorageTek, with its T10000B media and drive. Mainframe customers are told that LTO tape is unsuitable for them because it is designed for less intensive use-cycles than the IBM and Sun/StorageTek mainframe-specific tape products.

There is a sixth generation of the LTO format on the roadmap, featuring a raw capacity of 3.2TB and 270MB/sec transfer speed. With the development of deduplicated and replicated high-capacity SATA hard drive storage arrays, where today's 2TB drives can hold 20TB of deduplicated backup data or more in virtual tape libraries or as straight filer-interface disk backup stores, the tape media and drive market has been shrinking over the past few years.

Customers prefer the faster backup speed of disk-based backup and also the very much faster restore speed from hard drive arrays. This is much, much faster than finding files by sequentially streaming through a tape drive once it has been mounted. However, where there is an enormous amount of data to be stored - petabytes of the stuff - then bulk tape libraries still have a lower cost than the equivalent deduplicated drive array storage alternative. CERN's Large Hadron Collider project will use tape to store the vast amounts of data it expects to generate.

Previously there were other formats competing with LTO, such as Quantum's SDLT and Sony's Super-AIT. Both are now effectively at the end of their life with no future generations planned. For mid-range and enterprise open system Windows and Unix/Linux servers, LTO tape is the sole remaining mass-use format.

The development of backup to distant data storage suppliers, offering a cloud backup service, is also helping to diminish the size of the tape backup market. The rise of these disk backup and cloud backup alternatives raise doubts as to whether or not further tape media and drive format developments will take place. Manufacturers have to see a profitable market into which they can sell products, in order to make research and development worth their while.

FujiFilm and Imation both manufacture LTO-4 media. So far, no other media manufacturer has said it will produce LTO-5 tape media. It would be surprising, but not impossible, if FujiFilm did not make LTO-5 media.

The format is LTO - Linear Tape Open - but if there is only one media manufacturer then the openness of the media vanishes. ®