Cover V11, I04




The ACM news wire had a link to an interesting article about storage capacity recently. Written by Anne Michaud for the Boston Globe (p. C2, 1/14/2002), the article says, "Engineers are beginning to perceive a wall at the end of the road of information that can be stored on a hard disk. Some say the wall is two years out, others estimate a decade. In either case, after unexpected capacity expansion in the last dozen years, experts say they are witnessing the beginning of the end."

Various researchers, however, are looking for ways to stave off this impending storage crisis. For example, a consortium led by Seagate Technologies and Carnegie Mellon University is researching a technology called heat-assisted magnetic recording (or HAMR). HAMR technology involves supplementing magnetic disk drives, which use magnetic heads to read and write data onto spinning platters.

According to Michaud's article, "As storage density grows, the bits are becoming so small that soon they will become unstable due to a phenomenon known as superparamagnetism. The solution is to use a more stable medium, but today's magnetic heads can't write data to such a medium. HAMR solves the problem by heating the medium with a laser-generated beam at the precise spot where data bits are being recorded. When heated, the medium becomes easier to write to, and the rapid cooling stabilizes the written data." According to Seagate, if implemented, HAMR technology could enable the magnetic data storage industry to extend its technological advancement for a decade or more beyond what could otherwise be anticipated. I look forward to seeing how this and other research into storage technology plays out over the next few years.

In this storage and backup focused issue of Sys Admin, Henry Newman contributes an article on I/O and performance-related topics. Newman has worked in the IT industry for more than 20 years. In positions with Cray Research and now at a consulting organization, he has provided expertise in systems architecture and performance analysis to customers in government, scientific research, and industry. His focus is on high-performance computing and advanced UNIX systems, and he previously wrote a monthly storage column for Server/Workstation Expert magazine. For Sys Admin this month, Newman starts at the beginning and discusses how I/O works from the application. In his next few articles, he plans to address the whole I/O path and the issues with performance and tuning for the server hardware, operating system, file system, and applications.

Sincerely yours,

Amber Ankerholz
Editor in Chief