I was wondering if there is any downsides from using rvm in a production server. What should I prefer, rvm or native installation and why?
Simplicity is always rewarded.
Rvm is a development tool. Since you will not be switching Ruby versions back and forth dynamically on a production server, it can do no good and could create arbitrary levels of pain and suffering.
Update: Ok, we've got some excellent comments and know more now. For one, rvm was in fact a production tool first. (Who knew?) It looks like if an application doesn't bundle its own gem environment, rvm will do it at the system level, and that could be useful.
So there probably isn't a single answer to this question. If only one application runs on the server, or if all server applications are, say, Rails3, then rvm will not be needed. But other scenarios will benefit from the environment management.