On 04/27/2015 11:38 PM, Peter Krempa wrote:
On Mon, Apr 27, 2015 at 22:11:40 +0800, Shanzhi Yu wrote:
On 04/27/2015 08:01 PM, Peter Krempa wrote:
The documentation states that for shallow block copy the image has to have the same guest visible content as backing file of the current image. This condition can be achieved also with a raw file (or a qcow without a backing file) so remove the condition that would disallow it.
(This patch additionally fixes crash described in https://bugzilla.redhat.com/show_bug.cgi?id=1215569 since it removes the code) --- src/qemu/qemu_driver.c | 10 ---------- 1 file changed, 10 deletions(-)
diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index 70bf7aa..f979d33 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -16815,16 +16815,6 @@ qemuDomainBlockCopyCommon(virDomainObjPtr vm, if (qemuDomainDetermineDiskChain(driver, vm, disk, false, true) < 0) goto endjob;
- if ((flags & VIR_DOMAIN_BLOCK_COPY_SHALLOW) && - mirror->format == VIR_STORAGE_FILE_RAW && - disk->src->backingStore->path) { - virReportError(VIR_ERR_CONFIG_UNSUPPORTED, - _("disk '%s' has backing file, so raw shallow copy " - "is not possible"), - disk->dst); - goto endjob; - } - Although a shallow blockcopy of file without backing file is semantically correct, but still feel a little weird. And, a shallow blockcommit of file without backing file will failed with error "error: invalid argument: top '/var/lib/libvirt/images/raw.img' in chain for 'vda' has no backing file"
Should libvirt post error when try a shallow blockcopy of file without backing file, just as shallow blockcommit?
I cannot reproduce the error above, could you please post steps to do that? or perhaps debug log from libvirt?
It is easy to reproduce. Suppose live guest xml looks like: # virsh dumpxml vm1|grep disk -A 8 <disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/var/lib/libvirt/images/raw.1430143276'/> <backingStore type='file' index='1'> <format type='raw'/> <source file='/var/lib/libvirt/images/raw.img'/> <backingStore/> </backingStore> <target dev='vda' bus='virtio'/> <alias name='virtio-disk0'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </disk> Then try a shallow blockcommit of file has no backing file # virsh blockcommit vm1 vda --top vda[1] --shallow error: invalid argument: top '/var/lib/libvirt/images/raw.img' in chain for 'vda' has no backing file
When copying from a single layer image with the --shallow flag I'm able to successfully copy both into a raw and a qcow2 file.
I also can do it. But a shallow block copy of file which has backing file into a raw file does not make any sense, right?
/* Prepare the destination file. */ /* XXX Allow non-file mirror destinations */ if (!virStorageSourceIsLocalStorage(mirror)) {
Peter
-- Regards shyu