https://github.com/kahun/awesome-sysadmin
http://cfenollosa.com/misc/tricks.txt
http://sysadmincasts.com/
Bash strict mode https://news.ycombinator.com/item?id=8054440
http://www.opsschool.org/en/latest/monitoring_201.html
https://syscoding.com/
http://sysadmin.it-landscape.info/
http://overthewire.org/wargames/