mysql service fails to start/hangs up - timeout (Ubuntu, MariaDB)

Question

I set up my first Ubuntu Server with Ubuntu 16.04, nginx, php7.0, MariaDB, nextcloud and external DynDNS using this tutorial here: Install Nextcloud 9 on Ubuntu 16.04

Answer 1

FYI:

In my case neither the solution of Vincent or Lw Bi worked exactly, I needed some further actions.

Disabling the profile through placing a link in /etc/apparmor.d/disable/ simply didn't work, I don't know why.

On the other hand, setting MySQL to complain mode didn't work either immediately.

:~$ sudo aa-complain /usr/sbin/mysqld

Setting /usr/sbin/mysqld to complain mode.

ERROR: /etc/apparmor.d/usr.sbin.mysqld contains no profile

I needed to add the lines:

/usr/sbin/mysqld {
}

to /etc/apparmor.d/usr.sbin.mysqld, and then I could set it to complain mode successfully.