Minimum: 2 GB (It will run on 1 Gig but do you really want to allocate a JVM to use ALL of your ram?)
Recommended: 4GB+ Depending on # of pads & concurrent connections.
I would recommend not running a production Etherpad service on a Virtual PC / VPS or any thing that will interfere with Java accessing the machines memory. You may struggle to build on a VPS depending on your providers swap memory space settings.
Just a quick one, worth posting cause it’s not well documented.
Thank you, I was struggling with installing this on my VPS.