Virtualmin is a very powerful and light control panel for Unix-based and of course Linux servers, written mostly in perl, being one of the favorites tools of administrators
The reason is simple, it very expandable and does not affect operating system on which is installed, unlike for example radical changes taking place by cPanel. The management is offered by it's own web server providing a web-interface for setting up all available services (Apache, NGINX, MySQL, PHP, mailserver, etc) and config files of the system.
MySQLTuner is a script written in perl which based to MySQL logs, it generates some pretty safe suggestions about which variables can be changed in MySQL config file for a little extra performance
First, we download the script and make it executable:
chmod +x mysqltuner.pl
Then we run it:
The following command displays a list of the IPs that are connected to our server ignoring the STATE of the connection (CLOSE_WAIT, ESTABLISHED, etc)
netstat -tn 2>/dev/null
-t flag tells netstat to display only TCP connections
and -n flag tells netstat command not to resolve IPs to hostnames
While stderr (2) redirection (>) throws at "garbage" (/dev/null) means that we just don't want possible errors to break our cute output we are trying to make.