Comment 1 for bug 1404180

This can be already done using VMTask.boot_run_command

https://github.com/stackforge/rally/tree/master/doc/samples/tasks/scenarios/vm

You just need to pass you .sh script that will run proper command like this:
https://github.com/stackforge/rally/blob/master/doc/samples/tasks/support/instance_dd_test.sh

So only thing that you need is to make such file and run benchmark.