Practical Linux System Administration

Chapter 6. Installing and Uninstalling Software

Installing and uninstalling software are basic system administrator tasks. You might not perform them daily, but these are regular tasks for you and your team to complete. Most often, you’ll install updates, which can be automated. Any new software you install should be accompanied by a business justification, a change control record, and a written understanding of security implications, if any, from the requesting party. Installing software with known vulnerabilities is an easy pathway for malicious actors to compromise your systems.

Uninstalling software also requires a change control record because of the potential danger of removing a package, directory, or library required by some other critical system or service function.

There are three software installation methods: installing from repositories using a package manager, installing individual packages downloaded to the local filesystem, and compiling source code. This chapter covers all three methods. There are two standard methods of uninstalling software: using the package management tool and, in the case of compiled software, using an uninstall process. A third, nonstandard uninstall method is manually uninstalling software by removing directories, libraries, and binaries.

Manual software removal is a tedious task that only senior-level sysadmins should perform. The sections in this chapter teach you how to install software by a particular method and then uninstall software ...