Networking: A Beginner's Guide
To improve your server situation, you can take the following specific actions:
Take advantage of the fact that the graphical user interface (GUI) is uncoupled
from the core operating system and avoid starting X Window System unless
someone needs to sit on the console and run an application. After all, X Window
System, like any other application, requires memory and CPU time to work, both
of which are better off going to the server processes instead.
Determine which functions you want the server to perform and disable all
other functions. Not only are unused functions a waste of memory and CPU
time, but they are also just another security issue that you need to address.
Linux, unlike some other operating systems, enables you to choose the features
that you want in the kernel. The default kernel you get is already reasonably well
tuned, so you shouldn't need to adjust it. If you do need to change a feature or
upgrade a kernel, though, be picky about what you add and what you leave out.
Make sure that you need a feature before including it.
All this chatter about taking care of servers and making sure that silly things don't
cause them to crash stems from a longstanding UNIX philosophy: Uptime is good. More
uptime is better.
The uptime command tells the user how long the system has been running since
its last boot, how many users are currently logged in, and how much load the system
is experiencing. The latter two statistics are useful measures necessary for daily
system health and long-term planning. For example, if server load has been staying
consistently high, you should consider a more capable server.
But the all-important number is how long the server has been running since its
last reboot. Long uptimes are a sign of proper care, maintenance, and, from a practical
standpoint, system stability. You often find UNIX administrators boasting about their
server's uptimes the way you hear car buffs boast about horsepower. This focus on
uptime is also why you hear UNIX administrators cursing at Windows installations
that require a reboot for every little change. In contrast, you'll be hard-pressed to find
any changes to a UNIX system that require a reboot in order to take effect.
If you are new to Linux, you might not be ready to commit the use of a complete
system for the sake of "test driving." Because the people who built Linux understand
that we live in a heterogeneous world, all distributions of Linux have been designed
so that they can be installed on separate partitions of your hard disk, while leaving
other partitions alone. Typically, this means that Microsoft Windows can coexist on
a computer that also can run Linux. Additionally, many Linux distributions can be