MySQL Server 5.6 only runs when making swapfile

Question

I am new to MySQL server. I have set up a dedicated MySQL server. I am aiming to install MySQL server version 5.6 and since version 5.6 is not available on the Ubuntu repository, I have to upgrade it myself. Unfortunately, upgrading the MySQL server is a pain.

Everything went smoothly up until starting the MySQL by using the command:

sudo service mysql.server start

It will issue an error:

The server quit without updating PID file (/var/run/mysqld/mysqld.pid)

I've searched far and wide on what's causing this error. Unfortunately, I have found none. Not until a colleague of mine suggested making a swapfile. And thankfully enough it worked! Right now the MySQL server is running smoothly.

I was just wondering what caused the error and what are the drawbacks in this kind of setup in the long run?