Jan 2017

By Default, htop is not installed on an appliance version of the MFEL, nor is it part of a minimal install on a software only ISO (although a customer could have added it themselves)

On a brand new appliance, you will have to either:

Update the repositories to be able to install htop, please check out this wiki page first (or the install will fail)
CentOs 7 no WGET install EPEL

Or

Just download the htop library, and install that

curl -O https://dl.fedoraproject.org/pub/epel/7Server/x86_64/h/htop-2.0.2-1.el7.x86_64.rpm

the above example is for CentOS 7, use the correct path for your CentOS version

Bear in mind that the htop version might change

The installation of htop is very simple, you just need to type in to the console:

yum install htop.