How do I run multiple boot2docker with a docker machine?

I am using a docker machine on Ubuntu 14.04. I have a virtual machine running boot2docker executed by the following command

 `docker-machine create --driver virtualbox dev `

      

        
        
        
      

    

I am trying to create another virtual machine by following

`docker-machine create -d virtualbox --virtualbox-boot2docker-url /home/<user name>/Downloads/rancheros.iso rancher`

      

        
        
        
      

    

It starts, displays a message

`Waiting for VM to start` 

      

        
        
        
      

    

then

 `docker@localhost password:`

      

        
        
        
      

    

waiting for a password.

I've tried the password tcuser

(seen it at # 405 on github) to no avail.

for VM dev: Boot2Docker version 1.6.2, build master: 4534e65