The Operating System
In this section, we are going to go into some detail about what makes a Linux
operating system. I am not talking about the "product" Linux or any of
the bundled distributions such as SuSE, RedHat, or Mandrake. Here, I am talking strictly
about the software that manages and controls your computer. The collection of functions that do all
the work are collectively called the "kernel".
Because an operating system
is of little use without hardware and other software, we are going
to discuss how the operating system
interacts with other parts of the various Linux distributions. I
will also talk about what goes into making the kernel,
what components it is made of, and what
you can do to influence the creation of a new kernel.
Much of this information is far beyond
what many system administrators are required to have for their jobs. So why go over it? Because
what is required and what the administrator
should know are two different things. Many calls I received
while in tech support and many questions posted to newsgroups could have been avoided had the
administrator understood the meaning of a message on the system console or the effects of making
changes. By going over the details of how the kernel
behaves, I hope to put you in a better position
to understand what is happening.
The contents of this discussion is based primarily on two sources. The first is my book
Linux User's Resource. The second is David Rusling's
"The Linux Kernel". In our seperate documents David and I covered different topics and in different
levels of detail, so you didn't get the full story by reading either one by itself.
Rather than rewriting everything from scratch, David has graciously given me permission to
include his material with mine. Perhaps "merge" is a better term than "include", because
in spite of much commonality between the two documents, one often included information that the
other did not include.