The real cost of switching to Linux

The jury is in. After years of experimentation with Linux in the enterprise, customers, analysts, and vendors are starting to sing a consistent tune about where Linux makes financial sense and where it doesn’t.

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Although Linux is often thought of as a free alternative to established OSes such as Windows and proprietary Unix

is it really cheaper when you add the costs of acquisition, migration, operation, and support? In other words, is the TCO (total cost of ownership) of Linux really lower than that of Unix or Windows?

The simple answer is this: The more fully an enterprise adopts Linux across its infrastructure, the more financial leverage it is likely to get out of up-front investments in the OS. Those investments, which can be considerable, include Linux training and tools, and the costs of migrating from a Unix or Windows environment. And that financial leverage is improving steadily as better management tools, more third-party vendor support, and more skilled Linux system administrators arrive on the market.

But the cost and benefit of switching are not equal for everyone. Unix-to- Linux migrations typically make financial sense because retraining costs are minimal while hardware acquisition costs drop significantly. In green-field situations or for shops running a mish-mash of OSes, Linux can be a total financial no-brainer. But Windows-to-Linux migrations are more of a toss-up due to higher retraining and conversion costs, and lower hardware acquisition cost savings.

ROI or TCO?

Figuring out the TCO of Linux is not for the faint of heart. Several IT execs told us they skipped the exercise because the model would have been very complex, with too many unknowns and assumptions. “It’s really hard to break Linux TCO down. It’s such a fluid environment,” says Ray Duncan, M.D., technology director at Cedars-Sinai Medical Center in Los Angeles. “It’s hard to get a side-by-side comparison.”

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Laef Olson, an economist by training, decided to build a TCO model. “I just sat down with a blank spreadsheet and started making assumptions,” says Olson, currently vice president of technology for Cars.com, a division of  Classified Ventures. “Annual traffic growth. What do I pay for Web server CPUs? How many sys admins do I need per physical machine, and where will tools discount that down the road?”

Olson calculates that migrating to Linux would yield “a seven-figure savings” for Cars.com over a four-year period, assuming 20 percent to 25 percent annual traffic growth and a cost of capital (which he declined to reveal). But he notes that his model contained a few big “ifs,” such as the availability of Linux OS support from key third-party vendors. “A lot of it has to do with where you think the industry is going,” he explains.

Another important question is whether to focus on TCO or ROI when evaluating Linux. Most industry studies have focused on TCO — the all-inclusive costs of running specific workloads such as Web serving, file and print, and security applications. But that is changing. Robert Frances Group this year switched from doing Linux TCO analysis to ROI analysis.

“TCO doesn’t examine what you could save, what flexibility it will provide you, how much money you could make,” explains Chad Robinson, a senior analyst at the Robert Frances Group. “Those are the reasons you deploy something.” Moreover, adopting Linux usually includes one-time, up-front migration costs such as retraining and application integration, costs that are included in TCO but can only really be evaluated by looking at ROI.

“If TCO triples but ROI doubles then it should be deployed. You end up saving in the long run,” Robinson explains.

No matter which model you use, the financial benefit of switching to Linux from Unix or Windows is driven by four main cost categories: acquisition, migration, management, and support. Here are highlights of key issues in each of these areas.

Hardware and Software Costs

The benefit of replacing expensive RISC processor-based Unix hardware with commodity Intel boxes is one of the biggest factors driving Linux adoption. “Discount retailing’s a tight business, and we’re wicked cheap,” explains Burlington Coat Factory CIO Mike Prince, who has deployed about 2,400 Linux machines over the past three years, replacing many Unix systems. “Instead of having a superhorse you have a team of horses — you don’t have to have this genetic [RISC] wonder.”