[libvirt-users] how "safe" is blockcommit ?

Hi, currently i'm following https://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit. I 'm playing around with it and it seems to be quite nice. What i want is a daily consistent backup of my image file of the guest. I have the idea of the following procedure: - Shutdown the guest (i can live with a downtime of a few minutes, it will happen in the night). And i think it's the only way to have a real clean snapshot - create a snapshot with snapshot-create-as: snapshot-create-as guest testsn --disk-only - start the guest again. Changes will now go into the overlay, as e.g. inserts in a database - rsync the base file to a cifs server. With rsync not the complete, likely big file is transferred but just the delta - blockcommit the overlay: blockcommit guest /path/to/testsn --active --wait --verbose --pivot - delete the snapshot: snapshot-delete guest --snapshotname testsn --metadata - remove the overlay Is that ok ? How "safe" is blockcommit on a running guest ? It's possible that during the rsync, when the guest is running, some inserts are done in a database. Is it safe to copy the new sectors (i assume that's what blockcommit does) under a running database ? Or is it only safe doing blockcommit on a stopped guest ? Thanks for any answer. Bernd P.S. Is the same procedure possible when the guest disk(s) reside directly in a plain logical volume, without a file system in-between ? -- Bernd Lentes Systemadministration Institut für Entwicklungsgenetik Gebäude 35.34 - Raum 208 HelmholtzZentrum münchen [ mailto:bernd.lentes@helmholtz-muenchen.de | bernd.lentes(a)helmholtz-muenchen.de ] phone: +49 89 3187 1241 fax: +49 89 3187 2294 [ http://www.helmholtz-muenchen.de/idg | http://www.helmholtz-muenchen.de/idg ] wer Fehler macht kann etwas lernen wer nichts macht kann auch nichts lernen Helmholtz Zentrum Muenchen Deutsches Forschungszentrum fuer Gesundheit und Umwelt (GmbH) Ingolstaedter Landstr. 1 85764 Neuherberg www.helmholtz-muenchen.de Aufsichtsratsvorsitzende: MinDir'in Baerbel Brumme-Bothe Geschaeftsfuehrer: Prof. Dr. med. Dr. h.c. Matthias H. Tschoep, Heinrich Bassler, Dr. rer. nat. Alfons Enhsen Registergericht: Amtsgericht Muenchen HRB 6466 USt-IdNr: DE 129521671