The most attention-grabbing word associated with Linux and open-source software is “free.”
IT projects are costly, and the promise of removing license fees from the list of costs—such as those for training, integration and maintenance—has been a major factor in the Penguins rise to prominence.
However, the Linux distributions best-tailored for enterprise use are sold under per-machine, annual-subscription-price models that are far from free.
Red Hat Inc. and Novell Inc., producers of the two most popular enterprise Linux distributions, require per-machine licensing for their products, which they enforce through controlled availability of security and bug-fix updates.
Freely redistributable, license-cost-free alternatives to per-machine licensed distributions do exist, including free clones of RHEL (Red Hat Enterprise Linux) and a variety of so-called general-purpose Linux distributions.
While enterprise Linux distributions offer real benefits, they wont always be the best fit. Its likely that an organization with a significant Linux presence will end up with a mixture of per-machine licensed and free projects.
Companies should weigh the costs and benefits of completely free and commercial Linux alternatives and move forward with the best combination for their organization.
What are you paying for?
In exchange for the $350-to-$2,500 per-system-per-year cost for an enterprise Linux distribution from Red Hat, Novell or Mandrakesoft Inc., companies get a number of benefits, the most notable of which are phone- and Internet-based support services from the vendor.
Hardware and software certifications are another major benefit that enterprise Linux distributions can offer.
Enterprise hardware and software vendors that officially support Linux with their products certify their wares on a limited number of Linux versions—typically, RHEL and Novells SuSE Linux Enterprise Server—thereby reducing the compatibility scenarios for which they must test.
Another key benefit of enterprise Linux distributions is the promise of a long product life. Red Hat, SuSE and Mandrakesoft each state theyll provide security fixes for five years for their enterprise Linux distributions.
The longer supported lives and slower development cycles of enterprise distributions give independent enterprise hardware and software vendors a slower-moving target against which to certify their wares.
Finally, freely redistributable Linux distributions, by their nature, cant ship with important nonfree components.
This is why the base installations of Fedora or Debian wont play MP3s and dont contain popular applications such as Sun Microsystems Inc.s JVM (Java Virtual Machine), Adobe Systems Inc.s Acrobat Reader or Citrix Systems Inc.s ICA client—all of which ship with Red Hats, Novells and Mandrakesofts desktop-oriented enterprise Linux versions.
Because enterprise Linux vendors sell their products with per-machine licenses, they can negotiate licensing deals with intellectual property holders that dont allow free redistribution of their products.
For instance, Turbolinux Inc., a member of the ill-fated UnitedLinux group (which once also included The SCO Group Inc., SuSE and Connectiva S.A.), sells a version of its Linux distribution that includes Windows Media 9 codecs licensed from Microsoft Corp.
Theres no question that per-machine licensed enterprise Linux distributions offer significant benefits, but organizations that dont require particular software or hardware certifications or those that have little need for vendor-supplied support, should investigate lower-cost options.
In addition, the enforcement of per-machine licensing can be a pain to deal with. For instance, eWEEK Labs finds it much simpler to test or set up quick projects with RHELs all-free cousin Fedora than it is to use RHEL because we dont have to worry about assigning entitlements to our machines to fetch updates.
Enter the Clones
One free alternative to an annual RHEL subscription is roll-your-own RHEL.
All the source code for RHEL is open source and is freely available for download from ftp://ftp. redhat.com/pub/redhat/linux, as are the updates that Red Hat releases.
As a result, RHEL, in reconstituted form, can be had by anyone who opts to compile it.
For those who wish to avoid the rebuild process, there are a number of projects that have done it already.
These include White Box Linux, CentOS, Taolinux and Scientific Linux—all of which are clones of RHEL and, for the most part, differ only cosmetically from the real thing.
Another difference with these RHEL re-spins is the way they offer access to updates—most provide updates using the yum tool instead of the RHEL standard up2date.
Although you may not be able to persuade ISVs to support their software running on an RHEL clone, hardware and applications that are confirmed to run on RHEL should work in exactly the same way with one of its clones. At the very least, these options may serve well in testing scenarios.
Keep in mind, however, that all these clone projects are relatively new, and its not clear how good a job theyll do at keeping up with Red Hats updates and fixes in the years ahead.
Of course, if a clone project drops the ball, the update code will continue to be available from Red Hat for free, and compiling your own updates will always be an option.
Were not aware of a comparable clone project based on Novells SuSE Linux Enterprise Server, possibly because until recently, YaST (Yet another Setup Tool), SuSEs set of system configuration tools, was not distributed under an open-source license.
Now Novell has switched to the GNU GPL (General Public License) for YaST, and we expect to see similar projects branch out from SuSE Linux Enterprise Server.
The other major all-free alternative to per-machine licensed distributions are popular, noncommercial Linux distributions such as Fedora or Debian.
Fedora, the Red Hat-sponsored and community-supported distribution thats the most direct heir to Red Hats discontinued Red Hat Linux product, is very popular and up-to-date. Red Hat positions Fedora as an “enthusiast” distribution, which has left many wondering how suitable Fedora is for their needs.
Debian is another strong, popular candidate for enterprise use because it benefits from very large user and contributor bases and boasts one of the most stable development paces among popular Linux distributions.
Various commercial and noncommercial Linux distributions are based on Debian. A new project, UserLinux, has set out to build an enterprise-targeted Linux distribution based on Debian to rival the offerings of Red Hat and Novell.
While noncommercial Linux distributions lack the sort of direct, vendor-provided support of the enterprise Linuxes, the much greater popularity of these distributions results in more available information on the Internet, including surprisingly good support information from mailing lists.
Its also much easier to find precompiled software packages on the Internet for particular releases of Fedora or Debian than for various enterprise Linux products.
Linux distributions tend to ship with a lot of included software, but this is as much a necessity as it is a convenience because dealing with software thats prepackaged for your particular distribution makes system management much simpler.
UserLinux offers enterprises another
The UserLinux Project has set out to assemble an all-free, enterprise-class Linux distribution to compete with the per-machine-licensed likes of Red Hat Enterprise Linux and SuSE Linux Enterprise Server.
- Debian-based UserLinux will be based on the popular, noncommercial Debian distribution and will ship with an application set focused on business, although users will be able to take advantage of Debians well-populated software repositories.
- Updates The Debian Project provides security updates for its stable releases for a year after the next stable version ships. Debian stable releases move slowly; Woody, the current stable version, was released in July 2002 and is set to be succeeded by the next stable release, Sarge (on which UserLinux is based), in the next few months.
- ISV certifications The UserLinux team is hoping that adherence to the Linux Standard Base will lead to software vendor certifications, but the in-development standard for maintaining compatibility among Linux distributions must grow more mature and more widely embraced for this to occur.
- Support and services The UserLinux Project plans to make support available by pulling together a third-party network of UserLinux-affiliated commercial ISVs; time will tell how effective such a network will be.
Senior Analyst Jason Brooks can be reached at [email protected].
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