Linux has a number of useful tools that will give you full visibility into the utilization of resources on your system
Below are some basic tools and commands that will get you started.
iostat will tell you where disk IO is occurring.
htop will tell you which processes are running along with an overview of resource utilization.
sudo apt-get install htop
sudo apt-get install vnstat
Determine the version of the Linux Kernel and information on the specific distribution you are running.
uname -a && lsb_release -idrc