Difficult crossings: Windows-to-Linux migration barriers

Very few users have switched from Windows to Linux, or vice versa

Microsoft Corp. spent a considerable amount of time, money and energy trying to convince corporate IT shops that moving from Windows to Linux servers wouldn't make sense -- but at least for now, it's not clear it had to bother.

The heaviest users of the open-source operating system came from the Unix world, where the migration decisions were much easier because Linux environments are similar, skill sets transfer well, and developers can keep the same tools. Financial institutions especially also relished the chance to save substantial sums of money by moving to commodity hardware.

Yet even that group isn't abandoning Unix. Organizations don't walk away from years of investment, says Dan Kusnetzky, an analyst at IDC. The research firm's studies show that companies generally bring in Linux alongside their Unix servers, he says.

Fidelity Investments, for example, moved some of its Oracle databases from Sun Solaris boxes to Intel-based Linux servers because it enabled the company to merge database instances and reduce database licenses, according to Donald Haine, the former CIO and now a venture partner at the Boston-based financial services firm. But Haine predicts that the transition to Linux may slow now that new capabilities in Solaris 10 will enable Fidelity to achieve the server consolidation it seeks in its Sun environment.

"Why should I take the risk of moving some fairly critical applications when now I can do what I want to do?" Haine says. "I've had a huge investment in my [Sun-based] applications, and people get nervous when you move onto a new platform."

With even Unix users cautious about making a large-scale switch, it's not surprising to find that it's more difficult to ferret out IT shops that have made a major shift from Windows to Linux. Migrations from Windows to Linux happen on a limited scale with new Web applications. But they're hardly commonplace.

"Once a server application is up and running, it's very unusual for it to be repurposed," says Jonathan Eunice, an analyst at Illuminata Inc. "It's almost never done, and that's true of Windows to Linux and Linux to Windows."

The rare cases in which companies did migrate a Windows-based system to Linux, or vice versa, illustrate why such moves aren't going to turn into a hot trend anytime soon. The problem isn't just the hard work and the differing skills and development tools that are needed. The old adage, "if it ain't broke, don't fix it," tends to rule.

A Case in Point

State Street Corp. undertook a Windows-to-Linux project when it wanted to beef up the functionality of an internally developed fund administration application. The Boston-based financial institution also wanted to enable more employees to use the application, which collects data from a variety of sources, to prepare reports for outside customers. To add the new capabilities, the IT department determined that it would need to change the front-end user interfaces and redesign the database for the Windows-based application, which used Microsoft's Access and SQL Server databases.

State Street tends to view its IT landscape from the standpoint of scale. Mainframes, Unix and Linux are favored when the company plans to run the application at an enterprise or global level. Windows is typically the choice for smaller applications, when integration with the desktop environment is an important criterion or when the company won't have the resources to provide local support, says David Saul, a senior vice president in the office of IT architecture at State Street.

Since the fund-administration application was about to undergo a substantial rewrite, State Street figured it was a good time to move to IBM's DB2 for added scale and functionality. Shifting to Linux rather than Unix allowed the company to reuse some of its Intel-based hardware, at least on the development side, Saul says. Plus, State Street had performance and operational tools for its DB2 environment. Those types of tools "really weren't there at the time for SQL Server," says Saul. They're also lagging for Linux, but since the fund-administration application isn't transactional, those were less significant issues, he says.

"Given the business we're in, we do a lot of monitoring and auditing. From a security point of view, we make sure that people have appropriate access to the database and the operating system. So we bought and built a lot over time to do that," says Saul.

State Street gave Microsoft plenty of opportunity to keep Windows in the running, according to Saul. Microsoft even put on a workshop to show how the application could be redesigned to scale better. But the database ultimately became the critical factor in the decision, and the financial firm sided with IBM and its "class of the industry" DB2 optimizer, he says. Microsoft's upgrade to SQL Server 2000 was still in the works at the time.

"In our view, in this application, DB2 was a better choice as far as the scaling and the capabilities. It's a bit more forgiving because of its optimizer. When it develops its database plan to do its join, it does a better job than SQL Server," says Saul, although he does note that performance can vary by application based on how well the developer writes to SQL Server.

State Street rewrote the fund administration application in Java and redesigned the database, saving only the basic process flow of the original application. The rebuilt application went into production nearly a year ago.

In the coming months, the company plans to apply its analysis to a few more applications, including a mix of Windows- and Unix-based applications that are due for a significant rewrite. "If you're not doing a significant amount of rewrite," Saul says, "that takes away a lot of the incentive for rethinking the whole platform and everything else."

Saul says he can't see much point in moving infrastructure such as a mail server built on top of Microsoft's Active Directory to Linux. He says he'd be "ridden out of town on a rail" if users lost access to their mail folders. "One of Microsoft's major strengths is the degree of integration between the Web server and the applications," Saul says.

Even Ed Anderson, vice president of global product marketing at SUSE Linux distributor Novell Inc., says the company doesn't see much Windows-to-Linux conversion. "We've seen Linux servers being installed alongside the Windows servers," he notes.

Linux to Windows

Martin Taylor, Microsoft's general manager of platform strategy, says he has seen scattered cases of companies that tried Linux servers for their Web sites but decided to replace them with Windows boxes. That tends to happen if users encounter integration issues or spend more money for support or put more effort into maintenance than they expected, he says.

Hong Kong-based Tommy Hilfiger Corp. had three small informational Web sites that outside consultants built to run on Linux. When the company needed to revamp its Web presence, it faced the choice of staying with the open-source operating system or moving to another platform. CIO Eric Singleton says he was laying out a three-to-five-year road map for a Microsoft .Net-based environment at the time, and it made no sense to have the Web site as the only application on Linux.

"It was about a business decision based upon a bigger view and a personal belief that a model with more governance and proc?ess and structure -- what Microsoft represented -- was simply a better thing to do for the company than an open-source, less-governed model," Singleton adds.

Tommy Hilfiger is also in the process of phasing out its IBM AS/400-based wholesale, warehouse management, accounting, retail and back-office systems in favor of Windows-based applications, according to Singleton.

Turning Back to Windows

Dulles, Va.-based FLYi Inc., which flies under the name Independence Air Inc., has always been a Windows-centric organization. About 95% of its 105 servers are Windows-based, according to Stephen Shaffer, director of software systems. But the airline's reservation provider recommended Linux for its new Web site, so the company hired outside consultants to do the work.

Independence Air had hoped there would be a knowledge transfer from the Linux consultants to its Windows-focused IT staff so it could gain the skills to service the site and add functionality in Java. That didn't happen. "We went live, and we were still heavily reliant on the consultants to maintain the site," says Shaffer. "We ran into a whole bevy of problems that left us feeling kind of helpless."

Internal staffers struggled to configure Apache Web servers and BEA Systems Inc. WebLogic application servers to handle the load, and the site often went down as they did, says Shaffer. The network operations staffers had no Linux skills either, he adds.

Recognizing that the site would be generating 80% of the company's revenue and that trouble-shooting would be an ongoing problem, Independence Air made the decision "to go back to the Microsoft world," Shaffer says. It had taken six months and $400,000 for consultants to build the initial site. One consultant and two full-time internal staffers built the Windows-based site in three months, he says.

"You have to stick to your core competencies," says Shaffer. "Right or wrong, we're a Microsoft shop, and that's where our talent lies right now. You really need to evaluate whether moving to another technology in as rapid a time frame as we did is the right thing to do."

Stacey Quandt, an analyst at Aberdeen Group Inc., says she sees users migrate from Linux to Windows only when support is lacking or when they decide to move back to their familiar Windows environments. But that isn't happening much, since so few companies did even limited switching from Windows to Linux.

When Microsoft waged its battle to fight the spread of Linux, it worried most about new applications creeping into an organization, Quandt says. The reality, she says, is that "it's just hard to change."

Copyright © 2005 IDG Communications, Inc.

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