After making the move to Linode (finally!) I had some issues with getting the contact pages on this site and Penderry up and running. RVM was throwing an error about the sinatra gem missing. A quick scan of the error message and it was obvious that Passenger wasn't using my gemsets.

A bit of googling turned up this little snippet which, when placed in app/config/, will tell RVM to use the gemset associated with the folder.

if ENV['MY_RUBY_HOME'] && ENV['MY_RUBY_HOME'].include?('rvm')  begin    rvm_path     = File.dirname(File.dirname(ENV['MY_RUBY_HOME']))    rvm_lib_path = File.join(rvm_path, 'lib')    $LOAD_PATH.unshift rvm_lib_path    require 'rvm'    RVM.use_from_path! File.dirname(File.dirname(__FILE__))  rescue LoadError    # RVM is unavailable at this point.    raise "RVM ruby lib is currently unavailable."  endend