A great discussion on a potential problem for database servers with limited drive space (life EC2 small instances). The best solution is in the comments section so be sure to read through.
One very interesting thing I noticed with MySQL was that if you delete a database, ibdata file doesn’t shrink by that much space to minimize disk usage. I deleted the database and checked usage of /usr/local/mysql/var folder and noticed that ibdata file is still the same size. So the problem I face now is, how do I claim back this space?