Running Linux, Fourth Edition

Chapter 7. Upgrading Software and the Kernel

In this chapter, we’ll show you how to upgrade software on your system, including rebuilding and installing a new operating system kernel. Although most Linux distributions provide some automated means to install, remove, and upgrade specific software packages on your system, it is often necessary to install software by hand.

Non-expert users will find it easiest to install and upgrade software by using a package system, which most distributions provide. If you don’t use a package system, installations and upgrades are more complicated than with most commercial operating systems. Even though precompiled binaries are available, you may have to uncompress them and unpack them from an archive file. You may also have to create symbolic links or set environment variables so that the binaries know where to look for the resources they use. In other cases, you’ll need to compile the software yourself from sources.

Another common Linux activity is building the kernel. This is an important task for several reasons. First of all, you may find yourself in a position where you need to upgrade your current kernel to a newer version, to pick up new features or hardware support. Second, building the kernel yourself allows you to select which features you do (and do not) want included in the compiled kernel.

Why is the ability to select features a win for you? All kernel code and data are “locked down” in memory; that is, it cannot be swapped out to disk. ...