The responsible system administrator applies operating system patches to his system as they are released in order to protect his system against crackers who might attempt to exploit newly-discovered vulnerabilities in the software his server runs. Timely patch management is a crucial component of contemporary system administration practice. As of the time of this writing, Red Hat Enterprise Linux 5.1 has dozens of known security vulnerabilities that can be fixed by downloading patches.
Red Hat Enterprise Linux includes a tool called yum that automates routine patches. Yellow Dog Updater Modified, or yum, is a program that manages packages, resolves dependencies, and downloads new packages from the Internet as needed.
To update your computer’s software packages, from the GNOME desktop, find the Applications menu in the top-left corner of the screen. Navigate to the Applications/System Tools menu and launch the Software Updater program.
The computer will trundle for a moment and then display a list of updates available. Verify that all of the available packages are selected. Click the Apply updates button. A progress bar appears and packages are downloaded.
On some GNU/Linux distributions, an Import key window may appear asking permission to trust software published by the operating system’s distributor. If it does, verify that the displayed key ID is correct and then click the Import key button.
If a Reboot recommended window appears, click the Reboot now button. Wait while the computer reboots. Repeat these steps – rebooting and running the Software Updater – until there are no more updates to be installed.
For experienced system administrators who prefer to work from a command line, typing:
is equivalent to invoking the Software Updater program as above.