----- On Apr 3, 2019, at 5:27 PM, Eric Blake eblake@redhat.com wrote:
It is possible to create an external snapshot (an internal one is not possible, unless you stored the guest disk as qcow2 format embedded inside the partition rather than directly as raw format). Note that when you create an external snapshot, the partition becomes a read-only point in time (no further updates to that partition), and your new file.sn qcow2 wrapper file created by the snapshot operation stores all subsequent guest writes. (Well, unless you decide to do a commit operation to push the changes from the overlay back into the base file and get rid of the overlay)
Hi Eric, thanks for your answer. i tried it: virsh # snapshot-create-as --disk-only --name sn --domain sim error: unsupported configuration: source for disk 'vdb' is not a regular file; refusing to generate external snapshot name This is the snippet from the conf for the guest: <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native'/> <source dev='/dev/vg_san/lv_sim'/> <backingStore/> <target dev='vdb' bus='virtio'/> <alias name='virtio-disk1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </disk> I'm running SLES 12 SP4 with libvirt 4.0.0-6.13.x86_64. Any ideas ? Bernd Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH) Ingolstaedter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDirig'in Petra Steiner-Hoffmann Stellv.Aufsichtsratsvorsitzender: MinDirig. Dr. Manfred Wolter Geschaeftsfuehrung: Prof. Dr. med. Dr. h.c. Matthias Tschoep, Heinrich Bassler, Kerstin Guenther Registergericht: Amtsgericht Muenchen HRB 6466 USt-IdNr: DE 129521671