How do i protect a package from being removed by yum?

vaquitasos

$ cd /etc/yum/protected.d

Create a config file for the package. Put the names of the package(s) in the file.

$ vi cowsay.conf

In this case just:

cowsay

The output from yum when you try to remove the package.

$ sudo yum erase cowsay
Loaded plugins: fastestmirror, langpacks
Resolving Dependencies
--> Running transaction check
---> Package cowsay.noarch 0:3.04-4.el7 will be erased
--> Finished Dependency Resolution
Error: Trying to remove "cowsay", which is protected

Good for hardening operating systems using yum or prevent accidentally removal of packages.