Getting Started With Linux

Computerworld |

To hear some people tell it, Linux is taking the world by storm. Unilever, a $52 billion consumer products giant, is switching to Linux to run its businesses around the world. Major vendors such as IBM, SAP AG and Computer Associates International Inc. are porting mainstream business applications and utilities to the low-cost, open-source operating system.

But not every IT shop is out on the leading edge of Linux; many are just starting to explore the open-source phenomenon. For them, Linux's practical implications are a major concern. IT managers face day-to-day challenges such as how to perform version control and how to back up and restore data. They also need to know how much training their staffs will need and whom to call for technical support at 2 a.m.

The good news: You can do almost anything on Linux that you can do on a mainframe or distributed systems. The bad news: It will require you to learn some new concepts and terminology.

1. Version Control

You may think of the open-source community as worldwide chaos, with developers releasing dozens or hundreds of bug fixes and updates each month that need to be evaluated and tested before deployment. Actually, it's not that different from the computing environments IT managers have lived in for years, say some users.

"Microsoft is announcing a new security breach [that requires patching] almost every day," says Dan Agronow, vice president of technology at Atlanta-based weather forecasting service The Weather Channel Interactive Inc., which runs Weather.com. And mainframe vendors find highly pervasive errors in their operating systems just as often.

That doesn't mean open-source updates can't seem, well, chaotic. In the past year, Islandia, N.Y.-based CA has seen almost 20 versions of the operating system kernels for different flavors of Linux, says Vincent Re, chief architect at CA. If you're a business customer, you're likely buying a distribution from a major vendor, such as Red Hat Inc., SuSE Linux AG or The SCO Group, that tests the updates, packages them and sends them to customers through Internet services such as the Red Hat Network.

Vendors usually provide updates only for their own Linux distributions; customers must go to other software vendors for updates to other Linux-based utilities or business applications. (For example, Red Hat doesn't distribute Oracle Corp.'s Linux offerings.)

As with Unix, in the Linux world, version control is referred to as "package management," says Erik Troan, director of product marketing at Red Hat in Raleigh, N.C. Each package is a single file that comes with metadata containing critical information such as which version of the Linux kernel and which associated software is needed to run the file, he says.

Customers with strong Unix skills can test and evaluate the updates themselves, says Re. Version control tools include the Red Hat Package Manager, which can also manage updates from other distributors. The Caldera VolutionManager from SCO in Lindon, Utah, combines software distribution with services such as asset management and system monitoring. Third-party tools include CA's AllFusion Harvest Change Manager for distributed Linux systems and its Unicenter Software Delivery for Linux on the mainframe.

Update tools such as the Red Hat Package Manager aren't perfect, of course. Red Hat won't support rollback (reversing a software update if it doesn't work) until the next release of its Advanced Server and Advanced Workstation in the fall, says Troan. Rollback is already available in Version 1.2 of Red Carpet Enterprise from Ximian Inc. in Boston.

Customers also face uncertainty over whether the new patches will run older applications or device drivers. Linux "doesn't have the reputation for forward and backward compatibility" customers have come to expect from mainframe operating systems such as z/OS, says Re. Some distributors have also balked at including device drivers or other software from vendors that have refused to include the source code in order to keep it from competitors.

Jeff Davis, global technical lead at Amerada Hess Corp., uses Red Carpet Enterprise to update about 350 servers running various versions of Red Hat Linux. The tool lets the New York-based energy company create "channels" that automatically send updates for the Apache Web server to Linux servers but not to Linux desktop systems.

But just as with Windows or mainframes, no good IT manager applies those Linux patches willy-nilly. Instead, says Agronow, "you have a scheduled maintenance cycle." Agronow updates his approximately 250 Linux servers once per quarter, only after testing to be sure the updates are safe.

2. Support

You can get as much hand-holding as you want (and are willing to pay for) from the Linux distributors or better-known vendors such as IBM and Hewlett-Packard Co.

"Just because the development model is open doesn't mean the support model is any different than what you'd find with a proprietary OS," says Timothy D. Witham, lab director at the Open Source Development Lab in Beaverton, Ore., and a Computerworld.com columnist . Or, if you have the skills and mind-set, you can turn to the open-source community itself and get better support than you would from a vendor you paid, say some customers.

When calling IBM for support with its WebSphere application server, Agronow had to slog through a script of questions read by a first-level support technician before being referred to an expert who could solve the problem.

After migrating to the Tomcat open-source application server in June 2002, he used Web sites and forums to get his questions "out to many different experts all at the same time." Not only did Agronow get answers more quickly, but he rarely was told to upgrade to "the latest and greatest version" of the vendor's software to fix the problem, he says.

Major vendors such as IBM and HP offer round-the-clock service, as do Linux distributors such as Red Hat and SCO. "A number of Fortune 100 companies, such as Morgan Stanley, rely on our support every day," says Red Hat's Troan. Such support is included along with all upgrades and bug fixes with Red Hat's Advanced Server Premium Edition license for $2,500 per machine per year.

3. Training

If you're coming from a well-trained Unix shop, anywhere from a couple of days to a couple of weeks should be enough to get you going on Linux, say vendors, analysts and customers. Staffers coming from a Unix or Windows background will, however, need training on functions such as partitioning before managing IBM's z/VM mainframe operating system, says Re.

Becoming a Red Hat Certified Technician generally requires two weeks of training, with another two weeks to become a higher-level Red Hat Certified Engineer, says Troan. Agronow says he wants one to two years of job experience for a junior administrator and four to six years for a senior administrator.

Many customers, such as Amerada Hess' Davis, are skeptical about the value of the several flavors of Linux certification available on the market.

One hopeful note on training: Davis says Linux requires less ongoing training than Windows because there are fewer differences among the various flavors of Linux than there are between, say, Windows NT and Windows 2000. With Linux, he says, "we're not retraining our staff every time a new version comes out."

Best Practices Count

Overall, the customers and analysts say that critical data-center tools and processes are rapidly moving to Linux. "If you're coming from a background where you have the disciplines in place for communicating changes, making changes and doing upgrades, and you apply those disciplines, you're going to have success," says Agronow. "If you're in an environment which is a free-for-all, where things are constantly changing and there are no controls and no standards," he says, you're going to fail -- with Linux or with any other operating system.

Scheier is a freelance writer in Boylston, Mass. He can be reached at rscheier@charter.net.

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Robert L. Scheier is a veteran IT journalist based in Swampscott, Mass.

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