On 05/05/2014 01:03 PM, Eric Blake wrote: > On 05/05/2014 07:20 AM, Cole Robinson wrote: >> On 05/04/2014 10:59 PM, Chen Hanxiao wrote: >>> Signed-off-by: Chen Hanxiao <chenhanxiao@xxxxxxxxxxxxxx> >>> --- >>> tests/cli-test-xml/compare/virt-clone-clone-auto1.xml | 6 ++++++ >>> tests/cli-test-xml/compare/virt-clone-clone-auto2.xml | 1 + >>> 2 files changed, 7 insertions(+) > >>> +++ b/tests/cli-test-xml/compare/virt-clone-clone-auto2.xml >>> @@ -22,6 +22,7 @@ >>> <disk type="file" device="disk"> >>> <driver type="qcow2"/> >>> <source file="/dev/default-pool/newvm.img"/> >>> + <backingStore/> >>> <target dev="hda" bus="ide"/> >>> <address type="drive" controller="0" bus="0" target="0" unit="0"/> >>> </disk> >>> >> >> Hmm, what is actually going on here? I know latest libvirt added backingStore >> chain XML to the domain XML, but what does a bare <backingStore/> mean here? > > A bare <backingStore/> is intentional - it means "known end of chain". > In concrete terms, this XML > > <disk type="file" device="disk"> > <driver type="qcow2"/> > <source file="file1"> > <target dev="hda" bus="ide"/> > </disk> > > represents a qcow2 file that might or might not have a backing file (we > haven't probed it yet), while this XML > > <disk type="file" device="disk"> > <driver type="qcow2"/> > <source file="file1"> > <backingStore/> > <target dev="hda" bus="ide"/> > </disk> > > explicitly represents a qcow2 file with no backing store. The > distinction is present to allow for smooth upgrade from older libvirt > which didn't record backing information to new libvirt; in particular, > we want to eventually get to a point where the user has full control > over the backing chain at domain definition time (in 1.2.4, the > information is output only, but we are still working on getting the > information to also be parsed on input for 1.2.5). > >> >> Anyone on the libvirt side know if this is intentional? > > Yes. > Sounds good, thanks for clarifying. - Cole -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list