<html> <head> <meta content="text/html; charset=windows-1252" http-equiv="Content-Type"> </head> <body bgcolor="#FFFFFF" text="#000000"> <div class="moz-cite-prefix">On 12/06/2014 03:33 PM, Eric Blake wrote: </div> <blockquote cite="mid:5482B137.4050506@redhat.com" type="cite"> <pre wrap="">I just found out the hard way that we have a bug in snapshot-create-as, when I corrupted a guest. I was testing with an offline domain: # virsh dumpxml win64 |grep -C1 driver <disk type='block' device='disk'> <driver name='qemu' type='raw'/> <source dev='/dev/sda4'/> # virsh snapshot-create-as win64 --disk-only --diskspec hda,file=/var/lib/libvirt/images/win64.qcow2 --no-metadata Domain snapshot 1417850911 created # virsh dumpxml win64 |grep -C1 driver <disk type='block' device='disk'> <driver name='qemu' type='qcow2'/> <source dev='/var/lib/libvirt/images/win64.qcow2'/> # systemctl restart libvirtd # virsh dumpxml win64 |grep -C1 driver <disk type='block' device='disk'> <driver name='qemu' type='raw'/> <source dev='/dev/sda4'/> Even though we don't want to save the snapshot metadata, we DO need to save the XML change. Otherwise, the restarted libvirtd sees the wrong disk as the source; worse, if the user started the guest before restarting libvirtd, they run the risk of accidentally reverting to the pre-snapshot state and losing all changes they made in the meantime, perhaps even getting their guest filesystem into an inconsistent state. I'm out of time to get to a root cause or fix before next week, but wanted to report it now. I'm not sure if --no-metadata is essential to reproducing the bug, or if it happens in all cases. </pre> </blockquote> Hi Eric, I can reproduce it without "--no-metadata" option. Can you give the bug number if you have file it so that QE can track it I post a patch <a class="moz-txt-link-freetext" href="http://www.redhat.com/archives/libvir-list/2014-December/msg00369.html">http://www.redhat.com/archives/libvir-list/2014-December/msg00369.html</a>. It works for me after a simple test <blockquote cite="mid:5482B137.4050506@redhat.com" type="cite"> <pre wrap=""> </pre> <fieldset class="mimeAttachmentHeader"></fieldset> <pre wrap="">-- libvir-list mailing list <a class="moz-txt-link-abbreviated" href="mailto:libvir-list@redhat.com">libvir-list@redhat.com</a> <a class="moz-txt-link-freetext" href="https://www.redhat.com/mailman/listinfo/libvir-list">https://www.redhat.com/mailman/listinfo/libvir-list</a></pre> </blockquote> <pre class="moz-signature" cols="72">-- Regards shyu</pre> </body> </html>