If you have some older CentOS VMs for testing or cross-compiling, you may run into the problem that you can’t install or update the system via “yum” any more: # yum update Loaded plugins: fastestmirror, priorities Determining fastest mirrors YumRepo Error: All mirror URLs are not using ftp, http[s] or file. Eg. Invalid release/repo/arch combination/… Continue reading Get “yum” on old CentOS working again