How To Set Up Subdomain or multi-domains and Apache Virtual Hosts on Ubuntu 14.04 LTS

This post is about creating multiple domains/sub-domains or virtual hosts on a single VPS running on Ubuntu 14.04 LTS with LAMP stack. (for LEMP stack, see another good example here.)

Summary

1) Create an A record for your sub-domain that points to your droplet

2) Create a .config file for your sub-domain site in /etc/apache2/sites-available

3) Create the directory for your site in /var/www (or wherever you defined it was in the config file)

4) Enable the site in apache with: sudo a2ensite sub.yourdomain.com (or whatever you named your site in the config)

5) reload apache: sudo service apache2 reload

NOTE: the DNS record you create might take awhile to propagate

Switching MySQL 5.x to MariaDB 10.x on Ubuntu 14.04

If you are going to use MariaDB to replace existing implementation of MySQL in production environment, then you will realize changing a DBMS to one another has never been easier considering the risks of incompatible supported features and functionalities, unpredictable development time and resources, migrating a huge amount of data and so on. MariaDB has already succeeded as a "drop-in" replacement  for MySQL and is truly open source and more optimized, faster and safer.

Though being mentioned that Migration might become difficult after 2015, below is a few steps which I believe is quite simple to install MariaDB replacing MySQL on Ubuntu 14.04.x as I came across the same requirement switching MySQL 5.5.5 to MariaDB 10.1.14.