I was trying to get openmeetings working on an Amazon AWS instance today and I kept getting Java out of memory errors. I fixed this with this simple solution I found:
This fixed my problem and allowed the java application to start with a limited amount of memory. Try this out if you have the same problem on a server with a limited amount of memory. There is an in-depth discussion of this problem here: https://wiki.csiro.au/pages/viewpage.action?pageId=545034311.