XenFaq - Xen Wiki2. Booting Xen 2.1. I get an error from Xen... (console output starting "(XEN)") (XEN) Initial guest OS requires too much space (XEN) (8MB is greater than 0MB limit) Check that you are correctly specifying the dom0_mem command line option for starting Xen. Note that: dom0_mem=512M should work in recent versions while older versions such as 2.0.5 require the memory specification to be in kilobytes,
