This page is intended at giving guidelines on what needs to be defined in a Debian VM template file, to make sure it runs Debian fine (for instance booting an image prepared along the guidelines in OpenNebula/PreparingDebianVmImage).
The OpenNebula (3.2.x) reference documentation is at : http://opennebula.org/documentation:archives:rel3.2:template
Drive mappings : make sure to use UUID= or LABEL= definitions in /etc/fstab, as the mappings in the booted kernel don't necessarily obey those set in DISK:TARGET settings in the VM template file.
libvirt/KVM architecture support : you may wish to change the default arch = "i686" in /etc/one/vmm_exec/vmm_exec_kvm.conf and set explicit values for OS:ARCH mandatory attribute in every VM template, according to the choice of node host arch vs VM image system's arch that you need (see http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=673173 for a discussion).