I'm new to Geoserver, Ubuntu and Java, but have downloaded a virtual machine from gisvm.com and am getting up to speed. I got as far as configuring it with some fairly large shapefiles from a project I've worked on previously.
My question is related to a problem which I see if I show the shapefile using the OpenLayers layer preview option. I see an error 'OpenLayers map preview code="internalError" Rendering process failed. java.lang.OutOfMemoryError: Java heap space'. Googling has led me to plenty of Java command line options to increase heap space, but I have no idea if this should be applied to an environment variable, in a startup script or as a part of the Geoserver config. Can you help me to understand what I need to edit to get this working? I'm also wondering if I should be splitting my shapefile into smaller pieces and so any guidelines on this matter would be helpful too.