Currently our production server runs in system ruby. Passenger handles our rails apps.
Should I move to handling my entire ruby stuff using rvm? What advantage can rvm give me in a production environment? Please advise. I'm a beginner in handling servers. I would need to run one or more apps in the same big server box using passenger.
if I use passenger via rvm, should I install passenger gem for every ruby I install?
If you don't absolutely need to have multiple ruby versions running at the same time I don't see any reason to use rvm. A gemfile and bundle should be good enough to keep the right gems associated with the right application
If you just want to have another version of ruby installed than the system provided, you can compile your self from source or use something like ruby-build.
Rvm does a lot of magic with user PATHs and changes behaviour in the interactive login shell that does not make sense to do on an production server. If you really want two or more versions of ruby (maybe jruby for the application and mri for scripting), rbenv or just setting your PATH right is a better idea.
rvm will allow you to use latest patch level of your ruby, this includes security patches - which is the main reason for switch
as for running multiple apps on one server the best solution is to use one instance of nginx as a proxy forwarding to unicorn or passenger standalone per app.