* Questions and answers about LTO
Today, we have a question about Linear Tape-Open storage.
Reader, Daniel Fader of Fort Lee, N.J., writes, “What’s all this I hear about LTO-3 tape, anyway? How is it different from LTO-2? What about all my LTO-2 media? Is there going to be an LTO-4? Should I wait for LTO-4? Should I care? And what’s this I hear about it having worms? We already have enough trouble with software bugs and compliance issues without having to worry about that!”
Dear Mr. Fader,
You have nothing at all to worry about here. “LTO” is an abbreviation of Linear Tape-Open, a technology first released by the storage industry about four years ago. Companies such as HP, IBM, and Seagate got together and developed an entirely new format based on what they felt was the best of existing technologies. It has been a big success since its introduction, and LTO-3 will be the latest iteration of this line.
Let’s take your questions in order.
LTO-3 differs from LTO-2 in at least two important aspects. First, LTO-3 moves data at up to 80M byte/sec, twice as fast as LTO-2. Next, and just as useful, is the fact that the new standard allows users to store 400G bytes of data on a single cartridge (twice that if compression is used), again two times what the previous standard allows.
Your old LTO media will still be useful and usable. The LT industry group has made sure that each succeeding generation of LTO can read and write to the previous generation of media – but only at the old media’s native speed. In addition, LTO-3 will be able to read – but not write to – LTO-1 media. This means you can continue to read and write to LTO-2 tapes on an LTO-3 machine, albeit at a slower speed and storing less data. Don’t plan on writing to those old LTO-1 tapes however.
Yes, there is going to be an LTO-4 – plan on it appearing in about two years. Again, expect both throughput and storage capacity to double.
As far as waiting for LTO-4: if your tape hardware is aging, or your needs have doubled, it probably makes good sense to look at what is available now. An increasingly wide selection of third-generation LTO devices is becoming available.
Should you care? Yes, you probably should.
Now as to this business about worms. Actually, Mr. Fader, the reference is to WORM – Write Once, Read Many – tapes. Once a piece of WORM media is written to, the data cannot be changed. WORM media contains special technology that protects its contents. Most importantly, every regulatory agency of which I am aware accepts WORM when it wants to assure compliance with a requirement for data immutability.
Expect to see a lot of LTO-3 in everything from stand-alone drives to tape autoloaders to libraries that scale well into the multiple petabytes range. You will have your choice of both high speed SCSI (160M byte/sec and 320M byte/sec) and Fibre Channel connectivity.
LTO-3 is likely to play a significant role in providing relatively low-cost storage if your company is moving into information lifecycle management (ILM).
Thus Mr. Fader, LTO-3 can help you with some of your compliance issues and – putting the most cheerful spin on this that I can – it can help you preserve your software bugs as well!
Cheers,
Mike
