On 06/01/2013 02:27 PM, Richard W.M. Jones wrote: > On Sat, Jun 01, 2013 at 01:28:20PM +0800, Qiu Yu wrote: >> For others who might interests, if you use qcow2 image with OpenStack and >> choose LVM as image backend, nova libvirt driver will convert it raw when >> creating a new instance.
IIUC, that's the reason, why it converts to raw -- https://github.com/openstack/nova/commit/ff9d353b ------------------------- "This uses 'qemu-img' to convert images that are not 'raw' to be 'raw'. By doing so, it a.) refuses to run uploaded images that have a backing image reference (LP: #853330, CVE-2011-3147) b.) ensures that when FLAGS.use_cow_images is False, and the libvirt xml written specifies 'driver_type="raw"' that the disk referenced is also raw format. (LP: #837102) c.) removes compression that might be present to avoid cpu bottlenecks (LP: #837100) It does have the negative side affect of using more space in the case where the user uploaded a qcow2 (or other advanced image format) that could have been used directly by the hypervisor. That could, later, be remedied by another 'qemu-img convert' being done to the "preferred" format of the hypervisor." ------------------------- It also does it during nova-image-create. A small write-up on how/why -- http://kashyapc.wordpress.com/2013/03/11/openstack-nova-image-create-under-the-hood/ However, data injection using libguestfs will >> still assuming the it is qcow2 format, hence hit the above issue. Not sure >> it is a bug or not, probably one should specify "use_cow_images = False" to >> avoid the problem in this case. > > Yes, this sounds like a Nova bug. > > Rich. > -- /kashyap _______________________________________________ Libguestfs mailing list [email protected] https://www.redhat.com/mailman/listinfo/libguestfs
