Microsoft Windows 2000 Server and Windows NT Server rule the network operating system (NOS) roost. But as the results of a recent NetAdmin survey reveal, most networks are composed of more than one NOS.

Although the majority of survey respondents said they have Windows servers in their corporate networks, those servers are definitely not the only show in town. Microsoft shares the NOS spotlight with one or more other players in most of those networks. Only in a small percentage of cases is a Microsoft product the only NOS in use.

What this means for network administrators is that they must not only be knowledgeable about a number of network operating systems but they must also know how to make them work together.

Windows is everywhere—almost
As Figure A shows, a vast majority of respondents report that they have Win2K and NT on their networks. Novell NetWare and some flavor of UNIX can be found in over half of all respondents’ networks. And Linux ranks fifth in terms of its network presence, with Mac, OS/400, and others trailing far behind.

Figure A
It’s a Windows world—mostly.

How many servers?
Questions about the percentage of servers on which the various NOSs are installed also yielded interesting results. These figures show more than anything that the current corporate network comprises multiple NOSs. So it appears that network administrators would be better served to eschew NOS specialization and instead become well versed on multiple platforms.

Microsoft’s server presence
As Figure B shows, respondents reported that a Microsoft NOS was rarely installed on most of the servers in their networks.

Figure B
Only in a small percentage of cases is a Windows NOS the only show on the network.

In most cases, Windows 2000 Server and NT Server are installed on fewer than half of the servers in the network. This is somewhat surprising, given the typical assumptions about Microsoft’s dominance. More significantly, it further shows just how important it is for network administrators to have some level of expertise in a variety of NOSs. Many of those responding to the survey would probably say that they are Microsoft shops, but these results show that the issue is much more complex than that.

Novell’s following
Second to Microsoft in terms of network presence is Novell NetWare, which is installed on servers in nearly 60 percent of respondents’ corporate networks. Figure C shows that 18 percent of networks have NetWare installed on 41 percent to 80 percent of their network servers, which indicates that there are a fair number of strong NetWare shops are still out there. However, like Windows, NetWare is still not a majority player in most of its installations.

Figure C
Like Windows, NetWare usually shares the network burden with other NOSs.

UNIX and Linux
Just behind NetWare is UNIX, installed in just over half of the respondents’ networks. Interestingly, as shown in Figure D, UNIX is seldom run on more than half of the servers in the network. Linux lags behind UNIX in terms of its corporate presence but posts similar numbers in terms of its prevalence on company servers where it is used.

Figure D
UNIX and Linux remain popular NOS solutions.

Everybody else
According to the survey, other NOSs, including Mac OS X Server, OS/400, OS/2, and Banyan Vines, are used far less and run on far fewer servers in networks where they are installed. As Figure E indicates, none of the members responding to the survey run these NOSs on more than 60 percent of their servers. Thus, these NOSs represent a very small niche and are never the only operating system that companies use on their networks, which is not surprising.

Figure E
OS/400, Mac OS X, and others occupy a small number of company servers.

The challenge for network administrators
The obvious fact that these survey results indicate is that few company networks use just one NOS. That depends to a great extent, naturally, on the function each server plays in the network, but it’s important to note that companies almost never rely solely on one OS to do it all. Perhaps more interestingly, even though Windows 2000 Server and NT Server enjoy a significant presence in corporate networks, they are rarely the only NOS installed. Ultimately, this shows that the challenge for network administrators is to be able to manage more than one NOS and, in some cases, perhaps an assortment of several NOSs.