General Information
YellowDog Update Manager (yum) .
Checklist
View Installed Kernels
rpm -q kernel
Remove Old Kernels
yum install yum-utils
package-cleanup --oldkernels --count=3
vim /etc/yum.conf installonly_limit=3
Lock packages at specific versions to prevent them from being upgraded with “yum update”.
Install the version lock yum plugin
yum install yum-plugin-versionlock
Lock httpd package at the current installed version
yum versionlock httpd
List version locked entries
yum versionlock list
Remove httpd from being version locked
yum versionlock delete httpd
Remove all packages from being version locked
yum versionlock clear
Exclude packages from a yum update, temporarily and persistently.
Exclude one time
yum update --exclude=kernel*
Exclude persistently
vim /etc/yum.conf exclude=kernel* httpd*