[Yum] Prevent packages from being installed or updated

Even though it is recommended to always run the latest software version for bug fixes and security purposes, sometimes the package maintainers might have gotten too many donations and slip up on the next release.

And if that release is a kernel release, things might get ugly. Luckily, you can prevent yum from installing or updating packages by adding the --exclude parameter to your commands:

yum --exclude=PACKAGE update

this will update the system but not the packages named PACKAGE. Its scope is limited to the single command, so a second yum update will not exclude them.

Eg to exclude kernel packages:

yum --exclude=kernel* update

To make the exclusion permanent, edit /etc/yum.conf and add a line:

exclude=PACKAGE

[Fedora] VLC repository

In order to install VLC on Fedora, you'll need to add their repository to your sources.

Simply:

yum install --nogpgcheck http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-$(rpm -E %fedora).noarch.rpm

yum install vlc

If you find that you cannot play some media types, try installing these gstreamer plugins as well

yum install gstreamer-plugins-good gstreamer-plugins-bad gstreamer-plugins-ugly

[Yum] Add and manage custom repositories

In the latest Fedora versions, it is possible to add custom repositories to yum by creating a .repo file under the /etc/yum.repos.d/ folder following this structure:

[REPOSITORY_NAME]
baseurl=REPOSITORY_URL
enabled=1
gpgcheck=1
gpgkey=URL_TO_KEY

This will add and enable the repo available at REPOSITORY_URL signed by the GPG key found at URL_TO_KEY to your list.

Here's a couple of offical Fedora repos for Google Chrome and VirtualBox:

[Yum] Fix rpmdb open failed error

Although not as good as other package managers, yum has come a long way since I last tried it.

However, due to me installing software using the rpm command and other graphical package managers (it is bad, seriously), I managed to screw up something causing it to complain with a "rpmdb open failed" error.

The fix is easy enough though:

rm -rf /var/lib/rpm/__db*

rpm --rebuilddb

yum clean all

yum update