1. Fresh installed CentOs 7 on a Dedicated server / VPS
2. Root user access
Steps to install Virtualmin/Webmin on centos server
A. Check for yum repository updates if not updated first update yum repository
Yum update -y
this command will update your yum repository will latest rpm packages of all available rpms .
B. Now check perl & wget installation on your server.
rpm -q perl
rpm -q wget
If not installed than install these packages via
yum install wget perl -y
C. If both these installed successfully than proceed with virtualmin script download from their website (https://www.virtualmin.com/download.html)
this will download virtualmin install script on your server
Make script executable.
chmod 755 install.sh
Finally execute install script.
And sit back & take rest this will install virtualmin in few minutes on your server.
After finishing installation on ssh shall you need to perform post installation steps via browser.
Access virtualmin on browser https://youserverip:10000 and perform post installation as per you your requirement.