In-Depth

Linux Living in a Windows World

It may be nowhere near as prevalent on the desktop, but Linux is no stranger to running servers.

• By Emmett Dulaney
• 09/01/2005

While Linux is slowly making inroads onto the desktops of corporate America, its presence there is really nothing new. It has long been a behind-the-scenes workhorse running on many of the servers that power the IT backbone of those same companies. Its initial acceptance on the server side and among the open source enthusiast crowd far outstripped its acceptance on the corporate desktop side—primarily due to the sheer volume of corporate desktop applications available for Windows.

We have already reviewed several Linux desktop variants that are ready for prime time and poised to take on any of the deeply engrained desktop versions of Windows (see Redmond Roundup, "Desktop Linux: Ready for Prime Time?" June 2005). This time, we focus on the server side.

We've examined four variations of Linux and Unix server operating systems for Intel platforms that go head-to-head with Windows 2000 Server and Windows Server 2003. Two of the products are Linux variants—Red Hat Enterprise Server 4.0 and SuSE Linux Enterprise Server 9.0. The other two—OpenServer 6.0 and Solaris 10—are actually classified as Unix. We included OpenServer and Solaris because they also run on the Intel platform and directly compete with the other Linux operating systems we've reviewed.

Another similarity these four packages share is their utilitarian presentation. You wouldn't purchase any of these Linux/Unix operating systems because they come with an elaborate manual and pretty packaging. In fact, none of them have true, current printed reference documentation. They all include useful online documentation, however, and thus earned the same score for that category.

To best compare apples to apples and make the testing platforms and processes as similar as possible, I followed the same set of installation procedures before I got rolling. For every one reviewed here, I first installed the operating system. Then I added and configured the Apache Web server. I chose Apache because it comes with each of these operating systems and is the most likely component one would add to a Linux/Unix-powered server (see the sidebar "Why Apache?").

(Click image to view larger version.)

You Can Leave Your Hat On
Red Hat Enterprise Server 4.0
To many IT managers, "Linux server" is synonymous with "Red Hat server." As grandiose as that may sound, this speaks volumes about the popularity of the company and its products. Red Hat has been a pioneer in promoting Linux and a true innovator in a number of other areas like certification and developing an accepted package manager.

When you start installing Red Hat Enterprise Server, you'll choose between a graphical- or text-based method (see Figure 1). Being a fan of getting things done as quickly as possible, I first tried the text-based installation a couple of times. I kept getting into a jam where the installation routine told me an error had occurred, but then it exited without giving me any opportunity to go back or any other options to try and circumvent the error.

Figure 1. The Red Hat installation menu gives you a choice between graphical- or text-based installation. (Click image to view larger version.)

So I tried the graphical installation routine, which ran smoothly. I didn't encounter any errors until it asked me to swap CDs. I had downloaded and burned a set of four CDs from its site, yet it didn't identify any of them as being CD No. 2. Eventually, I was able to get around the problem, but it wound up being an unnecessary time-killer.

Why Apache? In trying to decide what one service to add to each server for comparison purposes in this article, I chose Apache, the open source Web server. I picked this because it's one of the most widely used services in networking today, and because it has a direct equivalent in the Windows world. Internet Information Services (IIS) is to the Windows-based server world what Apache is to the Linux/Unix world. Some will immediately throw up their hands and argue that I am all wrong because IIS also offers FTP, or because Apache also runs on other platforms, and so on. Those minor details aside, these two products exist for the same purpose and a Linux machine running Apache can fulfill the same purpose as a Windows Server 2003 running IIS. — E.D.

After you install services on your machine, you can choose which of those services others will be able to use through a simple radio button interface. One of those choices is "Web Server (HTTP, HTTPS)." Selecting this service only installs part of what it needs to function as a Web server. You have to install the HTTPS package later.

One thing I found particularly valuable was how easy it is to install the Security Enhanced Linux (doing so is actually enabled by default). This essentially hardens the server. If you don't want to completely install this, you can choose to disable it. You can also choose the Warn status, which acts as a middle state. With Warn, policies are not fully enforced in all cases and you are warned when they are denied.

One thing I found annoying is the need to enter a subscription number after the first reboot. Obviously, you couldn't have the number e-mailed to this system because you're installing an operating system from scratch. This eliminates any cut-and-paste possibilities for a 16-digit number combining numbers and letters. I typed the number in from the e-mail I printed from another machine only to keep getting told that the number I was e-mailed was already in use for another subscription (perhaps it thought the failed installs were another subscription). Again, the solution, which ended up being to simply register again, was not that difficult, just another time consumer.

After all was said and done, despite some minor glitches during the installation process, configuring and running the Web services was very simple (see Figure 2).

Figure 2. Configuring any Web service is simple with Red Hat Enterprise Server. (Click image to view larger version.)

The operating system performed smoothly and I encountered no problems. I spoke with an administrator at a large hospital who told me that he had seven machines running Red Hat providing various Web services. He had not needed to reboot any of them in more than a year.

SuSE on the Loose
SuSE Linux Enterprise Server 9.0
SuSE uses a fairly simple graphical installation. You have a choice between which version of YaST (Yet Another Setup Tool) to use for walking you through the process. No matter which one you choose, you'll end up spending some time doing the installation, even though the process is straightforward. You have a minimal amount of questions to answer as you work through a series of dialog screens. Should you need to revise or edit any information, you always have the option to go back.

Toward the end of the installation, SuSE asks if you want to test the Internet connectivity. If you say yes and it tests OK, then you have the option of downloading and installing patches that have been released since you burned the CDs. The default desktop is KDE, but you can also use GNOME if you prefer.

Figure 3. The YaST control center lets you install, configure and maintain packages. (Click image to view larger version.)

For the most part, I always believe in getting the installation done as quickly as possible and tweaking it later. In this case, however, I highly recommend doing the update during installation as it proves much quicker than running it later. Everything is configured with the latest updates and patches before the reboot, which saves time later on.

To add the Apache software, you first have to start YaST, then choose Software, followed by Install and Remove Software. Typing "apache" in the Search field brings up the interface shown in Figure 4. Click to add Apache and accept. SuSE automatically checks to see if you need to install any additional packages to resolve any dependency issues (it defaults to install, but you can deselect that option if you wish), then it installs the software.

Figure 4. Use the YaST interface to add the Apache service in SuSE. (Click image to view larger version.)

The YaST interface gives you access to a majority of the configuration utilities through one consistent-looking tool. By far, this is one of the biggest selling points for this operating system.

Not only do you use the YaST interface to install packages, but also to configure and maintain them. After installation, you make changes to the Web server by first starting YaST, then choosing Network Services, followed by HTP server.

Expanding Choices If you're willing to look beyond the Intel platform and to more Unix-based options, there are a few other operating system choices. Three of the most popular alternatives are: AIX: From IBM, version 5L is now available. Learn more here HP-UX: From HP, version 11i is now available. Learn more here Tru64: From HP, available for the Alpha platform. Learn more here — E.D.

Open for Business
SCO OpenServer 6.0
OpenServer is a variant of Unix (System V, release 5), not Linux. At first glance, that may not seem too significant because it also runs on the Intel platform like Linux, has a command-line utility with the exact same name and functionality and so on. In actuality, though, there is a big discrepancy that you'll have to consider more closely.

On the positive side, you can trace OpenServer back to the beginning days of Unix. That means it has years of stability and reliability to back it up. On the not-so-positive side, it can only run applications that were written specifically for OpenServer (including SCO Unix, SCO OpenServer 5/6, SCO Xenix and UnixWare 7 binaries).

That is one of the biggest negatives tossed about by those who scorn Linux—the availability of applications. If you think the number of applications written for Linux is small, then you'll need a microscope to find those written for OpenServer. Beyond the basics, however, I'd question how many applications you truly need to run with this type of server operating system. Still, those looking for something beyond the core set of services might have a tough time finding what they need.

OpenServer was the easiest to install by far. While developers often make an effort to create a graphical installation routine purely in the interest of aesthetics, OpenServer keeps the installation simple in the interest of saving an administrator's time, which is far more important. There are a few simple choices you have to make upfront (see Figure 5) before the installation dismisses you and completes all the remaining tasks on its own.

Figure 5. You install OpenServer with an easy-to-use text-based interface. (Click image to view larger version.)

Once you've completed the installation, the system boots into the XDT interface that OpenServer has always used. While this interface is simple to understand and use, it looks and feels antiquated. To get around this, OpenServer 6 now lets you choose the KDE interface. If you opt to use KDE, you get the same desktop as you would with any other KDE-based operating system. The system utilities run in both XDT and KDE, but running KDE unfortunately seems to accentuate their old-fashioned look and feel.

There is an Optional Services CD that comes with OpenServer. This disc has Apache, and you can easily install it through the Software Manager. Once installed, configuring Apache or any Web service running on OpenServer is simple and straightforward.

Small companies would do well to choose this as a solid and straightforward server operating system. One of the main reasons I stress small is because they should get more benefit from the operating system and not be as affected by its limited services. The operating system also works nicely when used as a platform for SCOoffice Server 4.1.

The Sun Also Rises
Sun Solaris 10
Solaris is Sun's Unix server operating system, and it has gotten better and better with each successive release. Version 10 is "optimized for running Web services and includes Apache and Tomcat software to let you deploy services right away," according to the Sun Web site. There are also security features prevalent throughout this version like file verification features and secure execution.

There are four different ways you can install Solaris, as you can see in Figure 6. The Interactive installation is best for most new installs. It first asks you the standard questions, such as language, networking and time zone parameters. It also asks questions about whether or not you want the CDs to automatically eject, auto reboot to occur after installation and so on. If you don't watch carefully, this can create problems with the system restarting and beginning the installation routine all over again if the first CD stays in the tray. I highly recommend changing the defaults to manual prompts and reboots.

Figure 6. Solaris lets you choose between four types of installation. (Click image to view larger version.)

During the installation, you can choose to install the documentation, the Java Enterprise System, the Extra Value Software (Validation Test Suite and Install Check) or packages from the Software Companion CD. Installing the entire distribution takes up 4,346MB, plus any other packages you add to that.

The CDE (Common Desktop Environment) starts after the first boot and initial data collection. Then it walks you through the rest of the installation. You select X servers through the kdmconfig utility.

I tried to get a number of different lab machines to a point where I could finish configuring the operating system and install Apache, but I always ran into one problem or another. Most of the problems related to an inability to change beyond the maintenance mode or to bring up the X interface.

None of the other operating systems reviewed here caused similar problems. Frustrated and out of lab machines, I had to move on without installing Apache or being able to test some of the other features of this operating system. Sadly, if you need support for this product, you'll have to purchase it separately. That makes it less administrator-friendly than some of the other choices.

Linux Versus Windows Server The availability of applications is a huge factor when comparing Linux to Windows on the desktop. There are more Linux applications every day, but the numbers still pale in comparison to what is available for Windows. When it comes to servers, the number of applications you need greatly diminishes. A PC user may run a dozen applications at any one time, but most of the time a server focuses on one or two tasks like Web hosting, serving as a firewall and so on. No one can deny that the number of services available for the non-Windows servers is smaller than those available for Windows-based servers. The question is which platform offers the highest return on investment in terms of cost savings, reliability and comfort level. The ROI on the initial purchase is easy to determine by simply looking at the costs of licenses for the various operating systems. What is harder to quantify is the administrators' comfort level. If you have seasoned administrators who have been working with Windows for years, there can be considerable cost involved in retraining them to administer Linux at the same level of proficiency. On the other hand, if you're hiring new administrators for new server implementations, you can save by starting from scratch with Linux. It would be ideal if the choices were always black or white, but you'll need to make fresh evaluations for every site in order to find the best choice. — E.D.

Run for Its Money
Of these four Linux and Unix server operating systems, I was impressed by three of them for their suitability to work in a business setting. Every one of them offered the administrative tools and stoutness necessary to function as a Web server or fulfill a similar purpose in a business environment.

Red Hat has a well-deserved, loyal following. It's widely respected as a solid operating system. OpenServer has a rich heritage, being based on the original Unix. SuSE is an administrator's dream with its YaST management tool. Support issues kept me from conducting a full evaluation on Solaris.

As with the desktop Linux variants we reviewed in June, I believe that Linux (and Unix) will make additional inroads into corporate server rooms this year and give Windows Server 2003 a run for its money.