Redmine

Ok , im new at ruby and my engliish sucks, i could install redmine in heroku , but i have a hosting account on hostmonster wich support RoR . so .. i decided install redmine there.

This is what i done:
Donwloaded redmine , put it on a new folder.
edited database.yml
i left the cgi file (if i remember fine there r 3)
and here its my problem :

when i make a db:migrate says me :
rake aborted!
no such file to load -- rails/all

So if someone can write a litte HowTo (here in the page isnt one for hostmonster) maybe will be great and i be gratufll for that.

Thnx for all and sry for my noob question