Thanks for the lead. Here is the part of the article from Datamation:
The data transfer rate may still be your key criterion even if you're using a tape library in a near on-line environment. That was the case at AT&T's Pricing Analysis Laboratory (PAL) in Basking Ridge, N.J., which processes and analyzes more than 2 billion phone call records per month. Instead of putting all of this data on disk drives, which would have been prohibitively expensive, AT&T uses high-speed tape libraries from Ampex (http://www.ampex.com) in conjunction with less expensive digital linear tape (DLT) libraries.
AT&T chose Redwood City, Calif.-based Ampex's high-end 19mm helical scan tape drives--called Data Storage Technology (DST)--because the company needed premium transfer rates to perform timely analysis of data for adjusting the prices of its phone rates on an ongoing basis. "Our tape drives have to keep up with our multithreaded servers [a Sun UltraEnterprise 2000 and a 22-CPU 6000], and the only way to keep them fed is with very fast transfer rates," says Steven Antos, division manager at AT&T's PAL facility.
AT&T is currently getting transfer rates of 12-13MB per second from DST, which is about three times faster than popular digital linear tape drives. With host-level changes, the company expects to hit 20MB per second--a transfer rate that rivals many disk drives. For less performance-intensive applications such as sample runs and tertiary backup, Antos uses the slower (and cheaper) DLT drives.
Of course, there's a large up-front cost for products such as Ampex's tape drives that are based on high-speed technologies. Libraries that use 19mm helical scan technology can cost more than $500,000, although prices may drop in the future if the technology gains more commercial acceptance, according to Freeman Associates. For now, Ampex's 2.4TB DST 412 library costs $160,000, and its 12.8TB DST 812 with four drives starts at $320,000. "It is pretty expensive, but disk would still be a lot more expensive," says Antos, "and disks require higher maintenance and they go down more often than tape." |
