Command Ref

nohup
nohup – to run command from ssh in background, so after session the program will still live.

screen
it is similar to nohup which allows processes to continue even after the ssh session has been closed.

Permission Stickyness
without group write permission
sudo chmod -R 2750 /home/demo/public_html

with group write permission

sudo chmod -R 2770 /home/demo/public_html/domain1.com/public/uploads

Recursive Chmod Tricks
(http://damonparker.org/blog/2007/06/27/recursive-chmod-tricks/)
Recursively chmod only PHP files (with extension .php)
find . -type f -exec chmod ug+x {} \;

check disk space
df -Th

*** System restart required *** 
cat /var/run/reboot-required.pkgs
above code to find what package needs restarting.

ubuntu only install security update
sudo apt-get install unattended-upgrades
sudo unattended-upgrades