On 14. 08. 19 13:27, Peter Krempa wrote: > On Tue, Aug 13, 2019 at 15:15:11 +0200, Petr Stodulka wrote: >> Hi guys, >> I had to move to the new laptop week ago and I screw migration of my virtual >> machines. I recovered my virtual machines on the new laptop (virsh define) >> using the backed up xml files, but I am missing any file with metadata about >> snapshots. The original storage is cleaned so I cannot take these files >> anymore. >> >> Using qemu-info I can see my snapshots inside the qcow images, but libvirt >> doesn't know about them: >> ########################################### >> # virsh snapshot-list rhlvm >> Name Creation Time State >> ------------------------------- >> >> # qemu-img info rhlvm.qcow2 >> image: rhlvm.qcow2 >> file format: qcow2 >> virtual size: 25G (26843545600 bytes) >> disk size: 2.9G >> cluster_size: 65536 >> Snapshot list: >> ID TAG VM SIZE DATE VM CLOCK >> 1 prepared 0 2018-09-05 11:06:06 00:00:00.000 >> Format specific information: >> compat: 1.1 >> lazy refcounts: true >> refcount bits: 16 >> corrupt: false >> >> >> ########################################### >> >> Is there any nice way to regenerate snapshot metadata for libvirt from >> the data inside qcow images? I have bunch of VMs so if there is nice way >> how to recover those data, you will make me really happy :) > > Hi, > > libvirt unfortunately does not support metadata-less snapshots so you > must recreate the metadata to be able to use them. If you didn't modify > your configuration of the VM between the time you took the snapshot and > the current point it should be fairly straightforward to recover them, > but it will require some manual steps. > > The snapshot creation api has a _REDEFINE flag which allows to create > the snapshot metadata without actually doing any disk changes. (virsh > snapshot-create --redefine). > > For this to happen you must prepare a definition of the snapshot. I'll > provide an example with anotations what to update: > > <domainsnapshot> > <name>1565701354</name> <--- this must be equal to the 'TAG' field in the qemu-img output > <state>running</state> <--- state of the VM at snapshot, you'll probably need to use shutoff as the VM was not running > <creationTime>1565701354</creationTime> <--- convert the "DATE" field to a unix timestamp > <memory snapshot='internal'/> <----- your snapshot is internal so this is ok > <disks> > <disk name='hda' snapshot='no'/> <--- entries here depend on your configuration, you need one line per disk, readonly disks must have 'no' as snapshot, others are internal > <disk name='vda' snapshot='internal'/> > <disk name='vdb' snapshot='internal'/> > <disk name='vdc' snapshot='internal'/> > </disks> > <domain type='kvm'> <--- this is the domain definition XML obtained by running a virsh dumpxml --migratable --inactive --security-info > <name>upstream</name> > <uuid>841752b8-9452-4078-a62b-8fd9a9af011c</uuid> > > [...] (trimmed irrelevant stuff but make sure to use full XML) > > <devices> > <emulator>/home/pipo/git/qemu.git/x86_64-softmmu/qemu-system-x86_64</emulator> > <disk type='file' device='cdrom'> > <driver name='qemu' type='raw'/> > <source file='/var/lib/libvirt/images/systemrescuecd-x86-4.9.5.iso'/> > <backingStore/> > <target dev='hda' bus='ide'/> > <readonly/> > <boot order='1'/> > <address type='drive' controller='0' bus='0' target='0' unit='0'/> > </disk> > <disk type='file' device='disk'> <---- these conform to the table above > <driver name='qemu' type='qcow2'/> > <source file='/tmp/pull4.qcow2'/> > <target dev='vda' bus='virtio'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/> > </disk> > <disk type='file' device='disk'> > <driver name='qemu' type='qcow2'/> > <source file='/tmp/commit4.qcow2'/> > <target dev='vdb' bus='virtio'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x0c' function='0x0'/> > </disk> > <disk type='file' device='disk'> > <driver name='qemu' type='qcow2'/> > <source file='/tmp/copy4.qcow2'/> > <target dev='vdc' bus='virtio'/> > <address type='pci' domain='0x0000' bus='0x00' slot='0x0d' function='0x0'/> > </disk> > > [...] > > </domain> > <cookie> > </cookie> > </domainsnapshot> > > > Use a document which you create with: > > virsh snapshot-create $VMNAME --redefine --current > > Use --current only for the most recent snapshot. > Thanks! It works as you wrote. All my snapshots are recovered. -- Petr Stodulka Core Services (In-place upgrades and migrations) Red Hat _______________________________________________ libvirt-users mailing list libvirt-users@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvirt-users
