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As more Unix systems are replaced with Linux, Unix administrators have to adjust their skills. While the two may look similar, there are some major differences.
Unlike a typical Unix operating system (OS) for servers, Linux is fundamentally open. In some cases, that developer-friendliness makes Linux appear as a disorganized OS, but this is offset by the additional opportunities that open source affords.
For the Linux beginner, here are five myths you'll hear about the server OS and why they're simply not true.
Linux myth 1: It's just like any other Unix server
It's true, Linux is related to Unix, but in the way that you are related to your grandparents: same blood, but a lot of different features. Linux administrators that come from Unix environments tend to get overwhelmed by the richness and speed of development on tools and features and wonder: "Why don't we just have one decent tool that does this?"
The answer is simple: because it's open source.
On your favorite Unix server platform, the OS vendor decides what's inside and picks the best tool. Linux is a compromise operating system, so it offers many tools to accomplish the same task. As a new Linux administrator, you'll pick tools from a vast amount of available resources.
Linux myth 2: All tools are structured the same
Due to the different origins of Linux tools and utilities, many aren't organized in the same way. For example, the ssh command offers a different method than the scp command for the same step. The ssh command lets a Linux administrator establish a secured remote connection, whereas scp copies a file over a secured channel. To specify which port the server should use, ssh relies on -p while scp goes with -P.
Linux beginners tend to get mad about that; why don't they just use the same option for the same functionality? The answer is simple: because of the different origins of both. The longer you work with Linux, the more examples you will find.
Linux myth 3: A functionality provided by the kernel always works
The Linux kernel is continuously under development. New features come out rapidly, and it's the community's responsibility to develop a tool or framework to work with these features. In many cases it happens; in some cases it doesn't. In Linux, you'll find a large list of attributes (for example, see man chattr, a command to change file attributes), of which many were never implemented.
Attributes are only one example of features that never made it to the daily reality of the system administrator. It's just one of the issues that come with an open source operating system, and a Linux newcomer has to deal with it as it transpires.
Linux myth 4: It isn't as powerful as Unix
I've never met a Unix admin who didn't think that Linux can be as powerful as Unix, and yet the myth persists. In fact, Linux is more powerful than most Unix platforms these days. Eighty percent of the world's supercomputers run Linux as their default operating system, which proves just how exciting the Linux kernel is.
The Linux kernel is so powerful because it is so accessible. For example, the /proc/sys file system gives direct access to hundreds of tunable elements. If that's not good enough, it's always possible to recompile the kernel to include new features.
Linux myth 5: It's a one-to-one replacement for Unix
A common mistake that Unix administrators make when migrating to Linux is that they treat the open source server as a replacement of their Unix server, and stop there.
Many Unix servers host mission-critical applications, from home-grown applications to SAP and Oracle. These apps run on Linux too, but the OS suits many other things.
Most of the servers on the Internet and most of the servers hosting the cloud run Linux. There's a whole new world of possibilities once you adopt it.
About the author:
Sander van Vugt is an independent trainer and consultant based in the Netherlands. He is an expert in Linux high availability, virtualization and performance. He has authored many books on Linux topics, including Beginning the Linux Command Line, Beginning Ubuntu LTS Server Administration and Pro Ubuntu Server Administration.