[libvirt-users] Help with understanding and solving snapshot problem

Hello Fairly new to libvirt. I’m hoping to both solve a problem with this question as well as learn more detail about how libvirt works. Using RHEL 6.4 and libvirt version is 0.10.2 and qemu-img version is 0.12.1.2 Using virt-manager I created a VM. Nothing unusual as far as I can see. I then added a disk. So I have a second virtio based volume which the guest then mounts as a separate filesystem. At some stage after that I created a snapshot of the system. I can’t delete the snapshot. The end result is I’d like to create a snapshot that excludes the second (much larger) disk - that is backed up via conventional backup systems. But the issue is first deleting the snapshot and my understanding of what its saying. So here is some basic info: # virsh snapshot-list host1 Name Creation Time State ------------------------------------------------------------ snap1-host1 2014-01-19 16:59:10 +1100 shutoff # # virsh snapshot-info host1 --current Name: snap1-host1 Domain: host1 Current: yes State: shutoff Location: internal Parent: - Children: 0 Descendants: 0 Metadata: yes So I try and delete it: # virsh snapshot-delete host1 --current error: Failed to delete snapshot snap1-host1 error: unsupported configuration: deletion of 1 external disk snapshots not supported yet Why does it say “external” in the above error, when the snapshot-info says its Location is internal? Are they not related ideas? The img file /var/lib/libvirt/images/host1.img is not being used by KVM. the snapshot files are in use instead: # virsh domblklist host1 Target Source ------------------------------------------------ vda /var/lib/libvirt/snap1-host1.qcow2 vdb /var/lib/libvirt/snap1-host1-db.qcow2 hdc - Querying them: # qemu-img info /var/lib/libvirt/snap1-host1.qcow2 image: /var/lib/libvirt/snap1-host1.qcow2 file format: qcow2 virtual size: 24G (25769803776 bytes) disk size: 3.5G cluster_size: 65536 [root@cocoa libvirt]# qemu-img info /var/lib/libvirt/snap1-host1-db.qcow2 image: /var/lib/libvirt/snap1-host1-db.qcow2 file format: qcow2 virtual size: 1.6T (1800279089664 bytes) disk size: 325G cluster_size: 65536 What have I done wrong and how can I correct this so I can discard the existing snapshot and have a snapshot of the system excluding the second disk (and optionally which I can re-take at intervals and discard old ones)? Many thanks, rolf.