Keeping a network running smoothly and efficiently takes teamwork—not the teamwork of a group of IT professionals, but the teamwork of various network operating systems (NOSs). Most companies don’t rely on just one NOS to run their network; rather, they combine the strengths of different NOSs to keep their networks running smoothly.

Results of a recent NetAdmin survey reflected this trend, with only a few respondents indicating that their companies use a single network operating system. However, the numbers alone may not tell the whole story.

IT consultant Todd Varble provided some insightful feedback on our survey results, so we asked him to elaborate on his perspective of how companies typically deploy their NOSs. Based on his experience with multiple business networks, he said that a combination of factors, including cost control, staff expertise, and NOS reliability, typically determine which NOSs companies use and how they use them.

Network function
Varble’s experience reflects our survey results: Company networks are composed of multiple NOSs—primarily UNIX OSs (including Linux), Windows NT/2000, and some NetWare (although Varble said that most NetWare he sees is considered legacy by the organizations that own it).

But what the numbers from our survey did not show is how those operating systems are used. Varble said that as a rule, he sees NOS tasks assigned as follows:

  • Windows NT/2000 is generally used for file and print services and as a Web server. With Microsoft Exchange, WinNT/2K is also commonly used as an e-mail/groupware server. According to Varble, this is usually set up in a load-balanced, server farm configuration. He added, “I’ve seen Windows being used for hosting databases, either with SQL Server 7 or 2000, but these databases are usually not considered mission critical.”
  • UNIX is often used to host large Oracle databases and enterprise-level applications such as SAP/R3 and PeopleSoft. ”While I have seen some UNIX e-mail servers running Sendmail, these do not seem to be as prevalent in the midsize corporate environment as the ubiquitous Exchange. UNIX e-mail systems do seem to be common in the largest environments, however.”
  • “Linux is making inroads,” Varble said, “but is still used for mostly noncritical, departmental functions, such as intranet Web servers, test boxes, and typical file and print services.”
  • Novell is used almost exclusively for file and print services.

Varble sees companies typically using their NOSs to perform specific functions that vary according to the size of the company and the applications it uses. In his experience, UNIX is used in large environments, while Microsoft’s NOS offerings are more popular in small and midsize companies. In addition, neither Linux nor Windows is usually relied upon to host mission-critical applications.

Why not one OS?
The big question that emerged from our survey and the responses to it is, “Why do companies use multiple NOSs?” The general conclusion is that no single NOS is flexible or reliable enough to do everything required of it on a corporate network. But a number of other factors have a bearing on the issue, including IT budget, functionality, the skills match, and compatibility.

The IT budget is obviously a big consideration—often the first consideration. In addition to the upfront expense of purchasing the NOS, companies must consider ROI and maintenance costs. Being able to purchase a network operating system is one thing, but companies must also determine what they stand to get in return and whether it’s worth the price over the long term. The cost of maintaining the NOS is an essential part of the equation, and that includes the IT staff and any technical support charges a company might incur should serious problems arise.

Another key consideration is whether the capabilities of the NOS match the company’s technical needs. For example, Windows might not be a good fit for large companies that require robust database functionality, but smaller companies looking for an e-mail or small database host may find that Windows is a perfect match.

It’s also essential to factor in the skills of the company’s IT staff and evaluate whether they can effectively administer the NOS. If not, the company must consider training, which will increase the cost incurred by choosing a particular NOS solution.

Integration into the current network infrastructure and into the business culture also affects the decision about which NOSs to use. Varble said it’s important to ask whether the NOS will work well with the current infrastructure, including other installed NOSs. In addition, the impact that the operating system will have on the users and IT staff must also be considered. This goes back to the issue of training, in terms of both the IT staff and the end users.

Hardware has a role to play
The NOS is not the only concern. Varble noted that in terms of network reliability, hardware platforms are also an important factor in the equation.

“We can debate Linux vs. Windows ad nauseum, but if they’re running on standard Intel boxes, they’ll both be less reliable than the HP-UX server designed from the ground up to be fault tolerant and bulletproof.”

While Varble noted that Linux and Windows are typically not used for mission-critical functions, he said that the x86/Intel platform itself, regardless of the NOSs used, is partly to blame for reliability issues.

“The x86/Intel platform has made good progress in the hardware reliability realm over the last few years, but it’s not there yet for true mission-critical reliability.”

Microsoft’s presence
It seems that there’s no middle ground when it comes to Microsoft: You either love its products or hate them. Our survey showed that WinNT and Win2K are the most-used of all network operating systems, but many members suggested that those numbers are deceptive in terms of interpreting Microsoft’s presence. Neither is as stable as other NOSs have proved to be, so they play a smaller, less-critical role in many organizations.

Varble contends that Microsoft’s dominance is not overstated. “Microsoft is an ever-present reality in every IT project, plan and proposal…. The only area Microsoft has yet to truly penetrate is the enterprise-level data center running mission-critical apps, and that is only a matter of time.”

Make the best of NOS strengths
Understanding how companies use their NOSs can help you take better advantage of the platforms you currently use and allow you make better decisions about which NOS might be the best solution for your company when making future plans.

We can draw these conclusions from Varble’s experience:

  • Microsoft’s NOS offerings are a good fit for small to midsize companies that require e-mail server, Web server, or small database hosting, and they are good for file and print serving in organizations of all sizes.
  • UNIX is a good solution for larger companies with massive databases and mission-critical enterprise applications.
  • Novell serves well on standard file and print servers.
  • Hardware has a strong bearing on network reliability and uptime, and x86 platforms still lag a little behind.