On Tue, Jun 21, 2011 at 07:36:23 -0600, Eric Blake wrote: > On 06/21/2011 07:14 AM, Stefan Hajnoczi wrote: > >> This new virDomainBlockCopy API is different. It can be used when you have a > >> disk image (no matter what kind) stored somewhere and you need to copy it > >> somewhere else. It takes two different and independent images, one currently > >> assigned to a virtual block device and a new unassigned one, copies all data > >> from the old one to the new one and reconfigures the block device to use the > >> new image. Neither of the image formats has to be even capable of backing > >> images. > > > > Right. > > This sounds related to my thread on snapshot capabilities, where if the > disk is not in a format where qemu can do a live snapshot, then libvirt > needs a command to pause guest I/O, libvirt snapshots the disk, then > libvirt informs qemu that the block device has a new image. It's all connected in some way, which is also why qemu will probably utilize common code to provide these functions. However, since BlockCopy is not a snapshot, it's about copying all data from one image to another qemu can do it all internally with a single monitor command to minimize the impact on running guest. Jirka -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list