Den 29/03/2011 15.41 skrev "David Sommerseth" <dazo at users.sourceforge.net>: > This makes me wondering how well it would go to migrate from SL6 to CentOS > 6, if all KVM guests are on dedicated/separate LVM volumes and that you > take a backup of /etc/libvirt. So when CentOS6 is released, scratch SL6 > and install CentOS6, put back the SL6 libvirt configs ... would there be > any issues in such an approach? I would not expect any issues at all, I would expect it to "just work". As long as you use CentOS6+/SL6+ (or Fedora 12+) *with* the libvirtd/virsh/virt-manager management tools, you shouldn't run into any major problems. This is because RH has implemented a stable guest ABI and stable guest PCI addresses, so the virtual hardware will remain the same on different KVM/libvirt hosts. > And what about other KVM based host OSes? That depends on a lot of things...in general, if you're not using one of the RH-based distributions mentioned above, use the latest version of the distribution in question, to hopefully receive some of the upstreamed bits from the RH-distributions. Luckily things are slowly stabilizing, so it should only be a question of time, before any distribution with a recent kernel, recent qemu-kvm executable and a recent libvirt version, should be compatible with each other in terms of moving KVM-guests around. The main problem is Windows guests, which easily chokes on hardware changes (forced reactivation of Windows or unbootable with BSOD). Each qemu-kvm version will behave differently, so moving from one major qemu-kvm version to another (0.1x -> 0.1y), will most likely change the virtual hardware seen by the guest, unless you have libvirt etc. configured to keep track of the guest hardware. If it's only Linux guests, it should work fine when moving the guests between any recent Linux distribution with KVM. Of course, if you don't use libvirt or a similar management solution, the hardware in the guest will likely change, for example causing your MAC-addresses of your NICs to change, etc, when moving to a new KVM host. Best regards Kenni