It's beginning to look like 2001 is the year Linux gets down to business. Systems managers who used to ask how Linux crept in the back door now ask if they can get the server to run it through the front door.
In Vancouver, British Columbia, for example, Metahost.net, a provider of J.D. Edwards and other Enterprise Resource Planning applications, runs Linux on a combination of two IBM z900s, the former System/390 mainframe. Metahost supplements the two big servers with hundreds of thin servers, according to Metahost spokesman Jag Sandhu.
The combination of high-end and low-end servers illustrates the flexibility that Linux has achieved as it moves into more mission-critical environments, a range of user spokesmen said.
In Rijswijk, Netherlands, Royal Dutch Shell runs Linux on a collection of 1,024 thin servers to analyze seismic data in the company's search for underground oil reservoirs. In Novato, Calif., shoe supplier Birkenstock Footprint Sandals runs its online store on a five-node TurboLinux cluster, which guarantees around-the-clock operations, said Howard Lee, marketing manager at Birkenstock.
In Atlanta, Weather.com, the online version of the Weather Channel and one of the top 25 most frequently visited sites on the Web, serves up weather maps, charts and reports using hundreds of Intel-based thin servers running Linux.
"We wanted an operating system that was extremely robust, lightweight and capable of working well with our Apache Web servers," said Mark Ryan, chief technology officer at Weather.com. Ryan called the task a "wide" one, or one in which a large set of front-end servers do much the same thing - serve static content to traffic that can vary from 5 million to 25 million users per day.
"For Weather.com, being on the bleeding edge is a competitive advantage," Ryan said. The site offers so much weather content at such a low cost of computing that it will be difficult for competitors to match, he said. As open source code, Linux is freely downloadable or comes with a low distribution price tag, compared to commercial server systems. But the back-end Oracle database system, which stores Weather.com's content and company information, remains on a Sun Microsystems server, Ryan added.
Weather.com's experience is reflected in the approach of another Linux user, Clearway Technologies, which distributes its customers' content to caching servers at 23 sites in the U.S. and Europe so it can be served to browser users more efficiently.
"To date, Linux has been very suitable to our needs. We have been able to trim down the Linux kernel to optimize it for our own ends," said John Rozen, vice president of operations at Clearway.
The flexibility of open source code - which gives users the right to modify code as they see fit - is leading to a growing acceptance of Linux in the ranks of information systems managers. It still tends to be used on servers handling well-defined tasks, such as Web serving, e-mail serving or application serving over the Internet. Running the back-end database server or transaction processing system, on the other hand, remains the domain of a mature Unix or proprietary operating system, users said.
Meanwhile, IBM and Sun are making it clear they will ensure that their Unix versions - AIX and Solaris, respectively - work with Linux. At the upcoming LinuxWorld, Sun will unveil a free version of its Sun Grid Engine that lets a Solaris server be hooked up to a Linux server in a distributed system, and share storage and files. The software was previously restricted to linking Solaris engines only, said John Tollefsrud, a spokesman for the product.
"We wish Solaris would be everybody's first choice," Tollefsrud said. "But we recognize Linux is there as a volume server system."
IBM, which has turned into one of Linux's biggest boosters, has equipped its AIX tool set to recompile Linux applications to run under AIX, giving Linux developers an added boost for their efforts, said Ross Mauri, IBM's vice president of development for its server group.
Linux will need more applications to assume a larger role in established enterprises as well as young Internet businesses. Marty Seyer, who helped establish the PowerEdge brand of servers during two and a half years at Dell Computer, said Linux servers are beginning to get the business software they need to gain market share at the expense of Windows and Unix. "I can't think of a major software vendor who's not committed to Linux," he said. Seyer is now the president and chief executive of Penguin Computing, a 100-employee Linux server builder in San Francisco.
Linux's current success comes at the still relatively low technical level of the 2.2 Linux kernel. Lead developer Linus Torvalds this month released the 2.4 kernel, which contains 64-bit memory addressing and data handling, along with improved capabilities to run four to eight processors. The new kernel now also includes a journaling file system, a subsystem that helps recover crashed servers.
Rozen said such features were valuable additions, but he doesn't worry that Linux might be too far behind more mature systems, such as Solaris or Hewlett-Packard's HP-UX, which have included file journaling for several years.
"A journaling file system? Sure I could put it to use. But so far Linux is keeping pace with the technology curve," Rozen said.