Open Source Community Preps Linux Kernel 2.4

Despite edging out Novell Inc.’s NetWare operating system to grab the number two slot in server market share during 1999, analysts say the open source Linux operating system doesn’t yet have a substantive enterprise presence. With the pending release of version 2.4 of the Linux kernel -- which is expected to provide a variety of scalability and manageability enhancements -- the Linux faithful are betting this will soon change.

Despite the hype that surrounds it, Dan Kusnetzky, program vice president for system software at IDC (, says Linux doesn’t enjoy the widespread acceptance of other operating systems in most enterprise environments. "Right now, Linux does not have a position as an enterprise operating system whatsoever, except in a few narrow market niches," he says. "But in those niches [such as Internet infrastructure, digital content creation, and high-performance technical computing] it’s a well-accepted model for computing."

This will change in time, most analysts agree, as the open source phenomenon continues its march to the enterprise. The forthcoming version of the Linux kernel, for example, is expected to introduce a number of important new features to Linux’s portfolio, such as advanced power management (APM) support, improved scalability in SMP configurations, and augmented support for peripherals.

Christopher DeMarco, a systems administrator who manages Linux, Windows NT, and Solaris platforms for computer reseller Neutron Computers Inc. (, says the 2.4 release will be an important one in regards to ratcheting-up Linux’s competitiveness among operating systems such as Windows NT/2000 and Solaris. Because of POSIX restrictions, DeMarco points out, Linux currently supports only 2 GB of memory; version 2.4 of the Linux kernel will double that ceiling to 4 GB. Windows NT and Windows 2000 today support 4 GB of memory. Windows 2000 Advanced Server supports 8 GB of memory.

DeMarco also points to the 2.4 kernel’s improved support for multithreading as yet another much-anticipated scalability enhancement. The upgrade shatters the 1,024 thread barrier of the 2.2 kernel, allowing systems with enough memory to support thousands of threads.

Version 2.4 of the Linux kernel is also slated to provide improved SMP scalability to the level of eight processors. In this area, Linux covered a lot of ground relatively quickly. Prior to the release of the 2.2 kernel in January 1999, deploying Linux on four-way SMP systems was considered a challenging enterprise. With kernel release 2.4 boasting scalability across eight processors, Linux appears to be knocking on Windows 2000 Advanced Server’s door.

Despite 2.4’s scalability enhancements, Nico Kadel-Garcia, a Linux developer and consultant with JOA Trades, says many of the implementations for which Linux is used today don’t yet require high-end SMP scalability.

"Most services don't need SMP," Kadel-Garcia says, pointing to the success of the Linux Beowulf clustering project as a scalable alternative to Linux on high-end SMP. "Mail and news and Web service are often better served by a carefully handled distributed network because they are usually bandwidth- and disk-bound, not CPU-bound."

Neutron’s DeMarco concurs, noting that one of his company’s application servers hums along very nicely on a dual-processor, Intel-based Linux box.

"I don’t particularly have any need for that type of application [high-end SMP] right now," he concludes. DeMarco acknowledges, however, that as applications such as Cold Fusion are ported to Linux, he’d strongly consider moving them from his Windows NT 4.0 Servers to Linux -- provided the SMP scalability was there.

Version 2.4 of the Linux kernel will do much to shore-up the open source operating system’s client-side story, Linux advocates argue.

"Version 2.4 of the kernel will provide better support for plug-and-play devices, and ISA plug-and-play has been improved," says Erich Forler, product development manager for Corel Linux at Corel Corp. (

"We’ve provided ‘backpatch’ support for things like USB in our current distribution, but being able to take full advantage of these things [APM, USB, plug-and-play] is something that is generally accepted as a distinct new advantage of the 2.4 kernel."

A developer’s-only version of a 2.4 "release candidate" --2.3.99-pre1 -- was unveiled mid-March on With 2.3.99x as the ramp-up, sources expect version 2.4 to be unveiled sometime this summer.

But that summer release date is a moving target. New additions to the 2.4 kernel were frozen in August 1999, and development work to incorporate the 2.4 kernel’s full feature set has progressed steadily since that time. Even at this late date, several features -- such as support for version 3.0 of NFS -- haven’t been incorporated into the 2.3.99-pre1 developer’s-only kernel release.

[Infobox] Linux 2.4

The open source community is hard at work on version 2.4 of the Linux kernel, which is expected to be unveiled sometime this summer. Enhancements should make Linux more competitive with Windows NT/2000 in markets where it couldn’t compete before.

Some of the features the new kernel is expected to support include the following:

Up to eight-way SMP

Up to 4 GB of memory

Multithreading beyond the current 1,024 thread limit

Advanced power management

Enhanced peripheral support -- including USB

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