Re: [Libvir] Next features and target for development

DL> This question comes up in other contexts than migration, too, for DL> example, when you want to start an image you just downloaded. I DL> think it would make sense if there was a common baseline in DL> libvirt that could tell you if a VM has any chance of running at DL> all - otherwise that logic will be scattered across lots of apps. The migration case is significantly more strict, though, at least for Xen. A domain image may start up on two machines that are different, but the same domain would not migrate from one to the other. On that note, how about a libvirt function that allows you to compare the capabilities of two hypervisors for varying levels of compatibility? A given implementation such as Xen could analyze the hypervisor and machine characteristics to provide a "compatible for migration" result, as well as a "can run on" result (and perhaps others). Something like the following: virIsCompatible(hyp1, hyp2, COMPAT_MIGRATION); virIsCompatible(hyp1, hyp3, COMPAT_MIGRATION | COMPAT_RUN); The former would return true (in the Xen case) only if both machines were the same bitness, processor revision, etc. The latter could, potentially, return true for a given domain across Xen and qemu, if that domain is fully-virtualized. -- Dan Smith IBM Linux Technology Center Open Hypervisor Team email: danms(a)us.ibm.com