On Tue, 2017-03-28 at 09:13 -0500, Robert Nichols wrote: > On 03/27/2017 12:31 PM, Patrick O'Callaghan wrote: > > I have a QEMU image snapshot: > > > > $ sudo qemu-img info /var/lib/libvirt/images/Windows10.qcow2 > > image: /var/lib/libvirt/images/Windows10.qcow2 > > file format: qcow2 > > virtual size: 20G (21474836480 bytes) > > disk size: 196K > > cluster_size: 65536 > > backing file: /home/poc/Win10/win10.qcow2 > > backing file format: qcow2 > > Format specific information: > > compat: 1.1 > > lazy refcounts: true > > refcount bits: 16 > > corrupt: false > > > > However when I try to restore the virtual disk I get: > > > > $ sudo qemu-img snapshot -a /var/lib/libvirt/images/Windows10.qcow2 /home/poc/Win10/win10.qcow2 > > qemu-img: Could not apply snapshot '/var/lib/libvirt/images/Windows10.qcow2': -2 (No such file or directory) > > > > I must be doing something obviously wrong, but can't see what it is. > > Hints would be appreciated. > > What you have is not a snapshot. A snapshot is created with "qemu-img snapshot -c <snapshot-name> <imagename>", and that is _not_ a separate file. That "<snapshot-name>" is not a file name but just a tag to identify one of possibly several snapshots within that "<imagename>" file. I did create it with the above line. Clearly I didn't understand where it was, or perhaps I inadvertently deleted it. Currently 'qemu-img snapshot -l <filename>' gives no output, so it looks like it's gone assuming it was ever there. (BTW the "no such file or directory" message could not be less helpful). > What you made was a copy-on-write image using /home/poc/Win10/win10.qcow2 as a backing file. You can make changes in /var/lib/libvirt/images/Windows10.qcow2 and not affect the backing file, but the backing file _must_not_be_changed_ during the lifetime of that dependent image. That c-o-w image cannot be restored to its original state. The way you do that is to throw it away and create a new one with the same backing file. I'm going to try to attach it to another Windows instance to see if it can be repaired. Otherwise, it looks like I'm screwed. Thanks for the information. poc _______________________________________________ users mailing list -- users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to users-leave@xxxxxxxxxxxxxxxxxxxxxxx
