Hi Everyone, I've installed Xen on my CentOs 6 machine using this guide: http://wiki.centos.org/HowTos/Xen/Xen4QuickStart So far, most things seem to be working fine. Here is the version of Xen installed: release : 3.10.27-11.el6.centos.alt.x86_64 version : #1 SMP Fri Jan 24 23:23:03 UTC 2014 machine : x86_64 nr_cpus : 4 nr_nodes : 1 cores_per_socket : 4 threads_per_core : 1 cpu_mhz : 3192 hw_caps : bfebfbff:28100800:00000000:00007f40:77bae3ff:00000000:00000001:00000281 virt_caps : hvm_directio total_memory : 32643 free_memory : 28827 free_cpus : 0 xen_major : 4 xen_minor : 2 xen_extra : .3-27.el6 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable xen_commandline : dom0_mem=1024M,max:1024M loglvl=all guest_loglvl=all cc_compiler : gcc (GCC) 4.4.7 20120313 (Red Hat 4.4.7-4) cc_compile_by : mockbuild cc_compile_domain : centos.org cc_compile_date : Fri Jan 24 20:49:25 UTC 2014 xend_config_format : 4 However, when I try to boot my Ubuntu 12.04 DomU (obtained from stacklet), this won't boot. This distro works fine on our other Xen machines which unlike this server, run a Ubuntu Dom0. Any ideas? When I try to launch the PV DomU, I see the pygrub screen, and when I hit enter, the DomU just crashes. Nothing appears in any of the DomU logs if I mount the disk to check. Help would be appreciated. Thanks Jonny