On 10/28/15 at 10:27am, Stefan Hajnoczi wrote: > On Sat, Oct 24, 2015 at 05:21:01PM +0800, Dave Young wrote: > > * block device > > For block storage migration, the problem is similar as memory. The original > > migration does not consider storage usage ratio it just copy all the sectors. > > This is equivalent to issuing discard requests. File systems can > already do that. > > The block/mirror.c code checks if sectors are allocated so this should > be possible to achieve this today (with guest cooperation). Yes, I did using hole punching in my code, I remember I did it on top of some old thread from Christoph Hellwig about puncing hole, not sure if they have been merged in qemu upstream. I lost my original patch thus I just put tarballs on the website, but seems I successfully generated the diff with official qemu-kvm-0.13.0. I have just put the hack patch of qemu to the url: http://people.redhat.com/ruyang/kvm/qemu-kvm-patches/qemu-kvm-0.13.0-block-migration-sparse.patch Another two patches for virtio qemu host side to work stay same directory as well. Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
