Stress Test CPU and Memory (VM) On a Linux / Unix With Stress-ng

Originally published at: https://www.cyberciti.biz/faq/stress-test-linux-unix-server-with-stress-ng/

I want test my Linux, OpenBSD, FreeBSD and Unix-like server entirely for high load and monitoring the health under stress. How can I stress out my CPU, memory, I/O, and disk stress and more with stress test tool on a Linux or Unix-like systems?