|
|
|
|
Taking the Measure of Tape Technologies
|
 |
|
September 30, 2002
By Steven Schuchart Jr.
|
|
In 1928 Dr. Fritz Pfleumer was granted a German patent for the application of magnetic particles to paper or film, and in 1953 IBM introduced the first reel-to-reel systems for data storage. Fast forward to today's tape data-storage market, which is awash in vendors jockeying for your company's mind and money. And no wonder: Although tape-drive sales remain flat, revenues are hovering around $2.7 billion per year, according to Gartner Dataquest, and that doesn't include the media or personnel and infrastructure costs.
Despite the fact that corporations spend a pretty penny on storage, some IT managers consider discussing tape-drive technologies about as scintillating as talking with a five-year-old about his favorite dinosaur. This is unfortunate, because a thorough understanding of the market and the technologies is vital for mapping a strategy to handle your company's burgeoning data-storage needs. Factors that might be a consideration in more complex systems, such as ease of use or OSs supported, don't come into play with a tape drive. The choice of one technology over another is based on up-front price, ongoing costs, speed, reliability and capacity. For example, say you're upgrading your tape systems. It may seem that buying drives that use media you own will take the sting out of the purchase price. But you also need to research the projected upgrade path of the tape technology to ensure it's not nearing the end of its life and you'll have sufficient support in the future.
|
|
As for capacity, you to know how much data you need to protect now and five years from now. Evaluate the growth rate you've experienced during the lifetime of your last tape technology, then add a healthy margin of growth. For help in calculating how much and how often to back up, see "The Hows and Whens of Tape Backups".
In addition, the technology you choose has to be fast enough to take advantage of your backup window. Make sure to chart backup-window lengths through your planned data-growth rate. The formula you use to calculate backup windows should take into account the data-transfer rate provided by the technology you choose--tape-automation systems can contain many drives, multiplying the data-transfer rate on a given backup.
It's also important to consider the speed of the interface you choose on the drives and automation unit. If you exceed the bandwidth capacity of the connection between the automation unit and the host device, your drives will not run at their maximum data rates.
This workshop focuses on tape technologies. For information on building the rest of your backup system, see our review of tape libraries, "OverLand Writes the Book on Tape Libraries,", and Buyer's Guides on tape backups and tape autoloaders.
The Big Kahuna
Quantum's DLT (digital linear tape) technology has the advantage in the tape market. This category includes DLT, SDLT, SDLT 320 and ValueTape 80. SDLT has enjoyed the most widespread adoption and follows the most aggressive technology path, staying a step ahead of its two closest competitors, AIT and Ultrium.
DLT holds the capacity crown as well, at 320 GB per cartridge, compressed, and sports one of the lowest per-gigabyte cost per cartridge (see table). DLT has long been a corporate favorite thanks to its adoption by Compaq Computer Corp. There has been some speculation that the long relationship with DLT would wilt with Hewlett-Packard's purchase of Compaq, but HP cannot afford to offend the DLT loyalists. We expect HP to continue to offer DLT/SDLT technologies, but with a long-term push toward its LTO (Linear Tape Open) technology.
Sony Corp. is on the third generation of its AIT (Advanced Intelligent Tape) technology, AIT-3, which sports the smallest form factor of the group. AIT-3 technology is used in StorServer's diminutive yet powerful S10000 backup appliance.
Exabyte offers its Mammoth and VXA technologies. The company is lagging behind competitors but has laid out a road map toward its Mammoth-3, which it says will sell for less than $3,000 and offer a compressed capacity of 625 GB and a compressed transfer rate of 60 MBps.
|
|
|
|
|
|
|
|
RSS
