mysql service masked after installing MariaDB

[Tony Arnold]

I'm trying to set up an Ubuntu server (15.04) but using MariaDB instead
of MySql. During installation, I selected LAMP server and then once
complete I installed MariaDB-server using aptitude. Aptitude offered to
remove MySql packages which I accepted.

However, when trying to start the mysql service, it fails with a message
saying the service is masked, viz:

sudo service mysql start
[sudo] password for tony:
Failed to start mysql.service: Unit mysql.service is masked.

How do I fix this? Or what is the best way to install ubuntu-server
using MariaDB?

Note, I need MariaDB because I am trying to restore a database that has
come from a system with the Aria storage engine as the default.

Many thanks in advance.

Regards,
Tony.
-- 
Tony Arnold, IT Security Analyst, University of Manchester.
T: +44 (0) 161 275 6093, F: +44 (0) 705 344 3082,
M: +44 (0) 773 330 0039, E: tony.arnold at manchester.ac.uk