If you're using mod_rails on a VPS with little RAM [ex: linode, slicehost], then there are a few things you'll want to do to save RAM when running rails. Here are a few things I did to allow me to run multiple rails processes on one linode slice. 1: Install a 32-bit OS Ruby uses twice as much RAM if you're in 64-bit than in 32-bit [and most other things do, too]. Use 32-bit! [linode has options to