"Linux is a family of free and open-source software operating systems built around the Linux kernel." - https://en.wikipedia.org/wiki/Linux

Most linux distros are built on GNU tools, and this article is relevant in distinguishing the importance GNU plays in the linux ecosystem: https://www.gnu.org/gnu/why-gnu-linux.en.html

Performance monitoring

Tricks

Configure a system to reboot on kernel panic

These lines should be added to sysctl.conf

# Reboot after 10 seconds if kernel panics
kernel.panic = 10
# Treat all oopses as panics
kernel.panic_on_oops = 1

Force reboot on corrupt system

For times that commands like reboot and shutdown are not available.

echo 1 > /proc/sys/kernel/sysrq
echo b > /proc/sysrq-trigger

See also

Distros

Init systems

Filesystems