There is a built in tool to remove old unused kernels thats installed onto the system. You can just as easily remove it and clean grub entries but this is an automated method and you can even set an option to keep x amounts. step 1 – install the yum utils package yum install yum-utils step 2 – run the package-cleanup to clean up old kernels package-cleanup –oldkernels –count=2 step 3 – if you want to set it so that you only keep X number of revisions on your system then edit /etc/yum.conf and add the following installonly_limit=2 enjoy!
There are many repositories that you can add onto your RHEL/CENTOS/FEDORA OS to install additional software. full list of repos can be found here http://wiki.centos.org/AdditionalResources/Repositories however is it safe to just add the repos and start installing packages? yes and no. We will configure priorities to setup the repos to keep packages from conflicting. Also you will want to protect the base OS installation so that there is less corruption/conflicts later on. step 1 – install the plugin if its not installed already yum install -y yum-plugin-priorities yum-plugin-protectbase step 2 – setup priorities for *-Base.repo that came with your OS… Continue Reading