Mrdu is a Ruby gem that makes it super easy to spawn a temporary MySQL instance off a RAM disk in Ubuntu. This allows for very fast database operations, which can be useful for speeding up large test suites.

This gem borrows heavily from the work done by these amazing people:

• github.com/mezis/mrd

• www.techusers.net/114/running-multiple-instances-mysql-mysqld-ubuntu-1004

• www.ducea.com/2009/01/19/running-multiple-instances-of-mysql-on-the-same-machine/

Install the gem at the command prompt:

$ gem install mrdu

$ mrdu

That’s it. This will reserve 512 MB of ramdisk and start a MySQL instance on port 3307.

There’s lot of options that can be specified as well. You can learn more about these options by running:

$ mrdu --help