The choice of server operating system (OS) is one of the most fundamental strategic computing decisions your customers
can make. This article outlines how Linux compares with the other major operating systems, as well as what the differences are among the various Linux distributions, or "distros."
Linux vs. peer operating systems
Within the operating system universe, it may seem that Windows is king, but that's not quite the case. Like Windows, Linux is expected to grow between now and 2011, according to IDC estimates; these are the only operating systems for which IDC predicts growth. Nathan Jang, manager of IT services at Netdigix Systems Inc., a Vancouver, B.C., company that specializes in managing servers, said that Linux runs about 90% of the servers he's seen that host Web pages or applications for external users.
Inside the firewall, Windows still predominates, in part because it has a more mature selection of applications to run on it. Jang said most companies still prefer the combination of Microsoft Outlook and Exchange -- on a Windows server -- so they can host email, share contacts, coordinate schedules and perform other day-to-day tasks internally. While Linux-based alternatives to the Outlook-Exchange combo do exist, end users aren't as familiar with them, and Jang said the open source programs aren't yet as mature as Microsoft's.
Linux can also be a big money saver for companies that currently have servers running Unix, said Nick Wilkens, president of MNX Solutions, a Monroe, Mich.-based company that specializes in remote Unix and Linux administration.
While Linux is open source and comes in free versions, Unix operating systems are usually closed source, can be
more expensive and sometimes run only on specific hardware. For instance, IBM's AIX, a Unix OS, runs only on IBM's servers. Conversely, the Linux kernel has been ported to a wide range of hardware, including the Intel chips many off-the-shelf servers use.
Linux is very similar to Unix, and Zachary said most Unix applications can be ported to Linux relatively easily. The primary difference between Linux and Unix is that "Unix" is a trademark owned by The Open Group, and any operating system that calls itself by that name has to be officially certified by The Open Group; Linux is not certified.
Unix systems do have benefits over Linux for mission-critical applications, Wilkens said -- for instance, AIX has APIs that can make it easy to diagnose hardware problems. But in many cases, there's no big deterrent for your customers that want to replace at least some of their Unix systems with Linux.
Choice of Linux distribution
There isn't any one vendor or version of Linux; the operating system's distributions differ largely in the specific components they include and their configuration tools and options. Sometimes, distributions are developed and supported by a company which is referred to as the distribution's vendor.
The two main Linux distributions at the enterprise level are Red Hat Enterprise Linux and Novell's SUSE Linux Enterprise. Both have free "community edition" versions -- Fedora and openSUSE, respectively -- but buying the enterprise version will entitle your customers to technical support and extra patches, as well as certification that the system supports many third-party applications, such as those from SAP and Oracle.
Red Hat is stronger in the North American market, and SUSE -- which started out as a German-based distribution before Novell bought it -- is stronger in Europe, Zachary said. After those two, the market fragments very quickly, he said.
Red Hat and SUSE both contain some elements that are closed source. But because the distributions are mostly open source, other vendors have derived their own distributions from them. Oracle announced its Unbreakable Linux, essentially a rebranded version of Red Hat, in 2006. But Zachary said he expects that Unbreakable Linux won't gain much traction except among existing Oracle customers who want a single vendor for their OS and applications.
If you're advising customers on a choice of operating system, Linux's integration benefits -- such as the fact that you can change a program's underlying code if you need to -- will likely figure into the decision. But several consultants we spoke with said they rarely or never touch Linux's source code; for them, cost is the biggest driver in adoption. Raven Zachary, The 451 Group's research director for open source, said price is the main reason people look to open source in general, including Linux.
Many Linux distributions are provided for free, but even those that cost money -- usually in the form of subscriptions for support, updates and extra tools -- are often cheaper than a comparable Windows server, according to Jang. When you include features such as clustering or multi-CPU servers, Linux can be orders of magnitude cheaper, he said.
Even if server administration isn't your core competency, offering Linux support can draw in more customers. Burleson Consulting in Kittrell, N.C., is primarily an Oracle consultancy, but it advertises Linux support on its Web site. The company's CEO, Don Burleson, said that's because the Linux version of Oracle's database is more powerful than the Windows version -- in fact, Oracle Database 11g shipped for Linux before it shipped for Windows. Being able to provide Linux support helps him attract customers who run Oracle on that platform, Burleson said.
The Linux operating system is the most recognized open source project, but there are many others -- such as databases, Web servers, ERP, CRM and ECM applications. In the final section of this series, we'll move on from Linux distributions to take a brief look at each of those, focusing on how mature the technologies are, where they are on the adoption scale and who the major vendors are.