last -x | grep shutdown | less

last reboot | less

last -x | head | tac

Examples of output:

runlevel (to lvl 0)   ... <-- first the system shuts down (init level 0)
reboot   system boot  ... <-- afterwards the system boots
runlevel (to lvl 2)   2.6.24-... Sat Sep 10 11:07 - 11:01 (2+23:34)

runlevel (to lvl 3)   ... <-- the system was running since this momemnt
reboot   system boot  ... <-- then we've a boot WITHOUT a prior shutdown
runlevel (to lvl 3)   3.10.0-693.21.1. Sun Jun 17 15:40 - 09:51  (18:11) 

du -a /directory | sort -n -r | head -n 5

*Replace directory with e.g. / to search the entire disk. Or /root for root only etc.

Update the following values in /etc/php.ini:

upload_max_filesize = 20M
post_max_size = 20M

Restart php-fpm

service php-fpm restart

Add the following to the nginx http block:

client_max_body_size 20m;

Restart nginx

service nginx restart