Upgrade Ubuntu 14.05 to Ubuntu 16.04

Here is the step: (but may be there is some lack here and there in the step)

At the first step I try to upgrade using this step: 

Ref:  https://www.digitalocean.com/community/tutorials/how-to-upgrade-to-ubuntu-16-04-lts

Then everything turn problem.. All services cannot started :( 

Here we go.. lets find out the solution :)

1. I notice that the version of php5 is already replace with php7. Which maybe the culprit of this problem. 

2. Mysql also cannot restart. 

3. Nginx problem because of the php5-fpm already deinstall and cannot be install again. 

Ok.. Lets start to patch;

1. uninstall all the package including all the dependancy of the package mysql.

#dpkg -P --force depends mysql-server mysql-server-5.7 mysql-common mysql-server-core-5.7 php5-mysql mysql-client-5.7 mysql-client-core-5.7 libdbd-mysql-perl libmysqlclient18:amd64 libmysqlclient20:amd64

2. uninstall all the package including all the dependancy of php

#apt-get purge php5-common php5-curl php5-json php5-mysql

3. unistall nginx 

#apt autoremove nginx

Then reinstall back

1. apt-get install mysql-server mysql-client mysql-common dbconfig-mysql

2. apt-get install php-fpm php-mysql

Changes in Mysql

#systemctl stop mysql

#nano /etc/mysql/mysql.conf.d/mysqld.cnf

datadir=/mnt/data/mysql

#nano /etc/apparmor.d/tunables/alias

alias /var/lib/mysql/ -> /mnt/data/mysql/,

#systemctl restart apparmor

#systemctl start mysql

Ref: https://www.digitalocean.com/community/tutorials/how-to-move-a-mysql-data-directory-to-a-new-location-on-ubuntu-16-04

Changes in php
Do some changes at 

#nano /etc/php/7.0/fpm/php.ini
;cgi.fix_pathinfo=1
cgi.fix_pathinfo=0

#systemctl status php7.0-fpm
#systemctl start php7.0-fpm

Changes in Nginx
#nano /etc/nginx/sites-available/default 

fastcgi_pass unix:/run/php/php7.0-fpm.sock;

Ref: https://www.digitalocean.com/community/tutorials/how-to-upgrade-to-php-7-on-ubuntu-14-04

Ref: https://www.digitalocean.com/community/tutorials/how-to-install-linux-nginx-mysql-php-lemp-stack-in-ubuntu-16-04

Others command;
apt-cache show mysql-server | grep Version    ; check version mysql 
dpkg --get-selections | grep php      ; check list package with php
lsb_release -a          ;check version ubuntu
nginx -t      ;test nginx config