On Tue, Jul 10, 2007 at 03:01:27PM -0700, Dan Smith wrote: > 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. Hum, we would probably need some logic like this between 2 hypervisor of the same type, but I'm afraid the matrix is gonna be a bit of hell if we want to handle all cases over time. It also feels a bit low level to me though I think I understand why you would like this :-) Daniel -- Red Hat Virtualization group http://redhat.com/virtualization/ Daniel Veillard | virtualization library http://libvirt.org/ veillard@xxxxxxxxxx | libxml GNOME XML XSLT toolkit http://xmlsoft.org/ http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/ -- Libvir-list mailing list Libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list