When Rackspace Managed Hosting started in 1998 to lease Internet colocated servers to customers, they went with Linux almost everywhere in an effort to keep costs down. In fact, heavy use of Linux was standard in the low-margin managed hosting sector. According to IT manager Eric Evans, "people would be surprised by how much they would save if they went with Linux."

Linux Servers and a Mix of Desktops

Evans supports a little under 200 servers for internal company use. Evans put all of the internal services that he could on Linux servers, including e-mail, file servers, print servers, DNS, and network monitoring. Only the financial application server and the sales force automation server remain on Windows, because the vendors don't have Linux versions yet. Linux comprises about 80% of internal servers.

Of the approximately 9,000 customer servers, Evans estimates that 60% are Linux, reflecting demand for cheaper Web solutions. Some customer services that Rackspace provides, such as domain registration and a customer portal, are also on Linux servers. The mandate to use open source whenever possible extends to the service provider role as well. Rackspace only uses Windows servers for applications that don't have an open source substitute.

According to Evans, more attention is paid to IT expenditures now that Linux has shown its value to the organization. "Anytime we need to deploy Windows, we choke on the price, and have to work harder to get the approval. Open source deployments are typically time, hardware, and that's about it."

Rackspace employs a large support department, so a sizable percentage of desktop users are technology-savvy. Although the officially supported desktop is Windows XP, employees are permitted to install whatever they want on their desktops as long as they give up support from the IT department. As a result of the loose rules, many technical employees have installed Linux. The IT department ensures that basic services will work for both operating systems, resulting in a hybrid desktop environment.

Everyone in engineering runs Microsoft Office on Crossover Office, an emulator for a subset of Windows applications. According to Evans, "Crossover Office is nearly flawless, and it's about as close as you can get to natively running Microsoft Office on a Linux workstation. I bought the plug-in first to play Quicktime videos, although I was skeptical. But it worked great, so I spent $60 on it for the full version." Evans likes it better than OpenOffice.org because he has absolute compatibility with Windows users now and in the future. And he was surprised that Microsoft Office is faster on Crossover running on Linux than it is on Windows.

Most nontechnical employees run Windows XP. Evans doesn't run Microsoft Active Directory though. Instead, he uses a Samba primary domain controller, backed by openLDAP as a Windows domain controller. A Linux server is used for all authentication. Evans concedes that he probably sacrificed some functionality with this choice, but found that it didn't actually matter for Rackspace. The bells and whistles that were sacrificed were not really needed. Evans and his staff also know that they can authenticate anything against LDAP, since it's an open standard. Whenever possible, open standards have always been preferred at Rackspace, to keep options open in the long term.

OpenNMS Saves Big

Rackspace doesn't have exact figures on how much a Linux migration saved, because they didn't migrate. But they are very aware of how much can be saved with specialized tools that run on Linux. OpenNMS, an open source network monitoring tool, is used internally for the approximately 200 company servers.

The cost savings are huge. Evans looked at OpenView, a proprietary competitor to openNMS from HP. But OpenView can cost tens or hundreds of thousands of dollars, depending on the installation. For Rackspace's needs, this product would cost about $200,000-$250,000 just for internal network monitoring and reporting, with $10,000 per year in maintenance costs. To use OpenView for their customers' servers was simply out of the question because the costs were too high. OpenNMS is a comparable open source free network monitoring tool. Rackspace purchases support from Blast Internet Services, the maintainers of OpenNMS, for just a few thousand dollars per year. Overall, the savings are quite dramatic.

There is a tradeoff for the savings, however. The HP product requires less ongoing administrative effort. Evans expects automation to improve as more administration tools are added to openNMS. The positive side is that Rackspace has some influence over what goes into the product. His staff is working now to expand openNMS so they can use it for network monitoring of their customers' servers. Their efforts will be incorporated into future versions of openNMS. Their code will help other users of the product, but the incorporation also benefits Rackspace by removing the burden of supporting the enhanced code.

Supporting Open Source Deployments

Evans finds that they have far lower administrative overhead with Linux than with Windows. "It's part of the Unix paradigm. We've seen as high as a 50-1 effective server-to-system-administrator ratio with Linux, but only 20-1 for Windows. Our average has probably been 35-1 or 40-1 on Linux."

Evans hasn't had much of a problem finding Linux expertise. "When I received applications, they came from monster.com and our Web site job postings. Rackspace is known as a desirable place to work because it is a startup, and employees have some freedom to run Linux on the desktop. Linux enthusiasts are happy to be here."

When asked what advice he has for IT managers thinking about a move to Linux, his basic message is that it's not as hard as you may think. "People overestimate the complexity of migrating to Linux. FUD (fear, uncertainty, and doubt) would have it that Linux is extremely complicated to set up and use, but that's just not the case. Even good Windows or network administrators pick it up. Linux is becoming more mainstream and mature, and is a perfectly capable platform for infrastructure, databases, etc. Don't fear it."

(This article is excerpted from the author's upcoming book, The Manager's Guide to Open Source, Manning Publications, September 2004.)

SIDEBAR

Rackspace Managed Hosting saved over $200,000 by using OpenNMS for network monitoring rather than a proprietary product. They continue to save several thousand dollars per year in support.

Open Source Products Used

• Red Hat Linux
• OpenNMS for network monitoring
• BIND 9 for DNS
• Sendmail and Postfix e-mail servers
• Samba primary domain controller
• OpenLDAP for Windows domain controller
• Crossover Office (proprietary product) to run Microsoft Office on Linux