>>I have found some post on qemu-devel mailing, not recommanding opening twice >>the file. (1 for qemu-img convert , 1 for online qemu).
http://lists.gnu.org/archive/html/qemu-devel/2010-09/msg01207.html "> > Will do. > BTW, my usage case for this patch is online backup the snapshot. That > means the image is opened with r/w by a running QEMU process, at the > same time, management tool can backup some snapshots already created > before on this image. Here management tool can make sure no one take > snapshot while backup snapshots. > If I read the QCOW2 code correctly(not easy to read...), no one > snapshots_offset/nb_snapshots in QCOW2 header, if you don't take a new > snapshot, so it's OK to copy the snapshot out from the image in my > usage case, right? Right, I _think_ this might happen to work, at least with today's code. Still I discourage having an image opened twice. It's not something that code changes will take into consideration." " ----- Mail original ----- De: "Alexandre DERUMIER" <aderum...@odiso.com> À: "Dietmar Maurer" <diet...@proxmox.com> Cc: pve-devel@pve.proxmox.com Envoyé: Lundi 6 Mai 2013 08:09:30 Objet: Re: [pve-devel] PVE::Storage::volume_has_feature But Maybe you are right, I have found some post on qemu-devel mailing, not recommanding opening twice the file. (1 for qemu-img convert , 1 for online qemu). Maybe it's works, but maybe something bad could happen. I'll do a patch to handle running parameter. Another thing we need to handle, it's full clone of a vm which is a qcow2 linked clone. I think we need to add backing files chain in qemu-img convert parameters. ----- Mail original ----- De: "Alexandre DERUMIER" <aderum...@odiso.com> À: "Dietmar Maurer" <diet...@proxmox.com> Cc: pve-devel@pve.proxmox.com Envoyé: Lundi 6 Mai 2013 07:52:10 Objet: Re: [pve-devel] PVE::Storage::volume_has_feature >>I thought it is dangerous to access a qcow2 snapshot while the file is in >>use? I'm think it's ok to do it online, I have done (small) tests last month. It's just read access, I don't think it can break the volume. But I can do test more extensive test again if you want. ----- Mail original ----- De: "Dietmar Maurer" <diet...@proxmox.com> À: "Alexandre DERUMIER" <aderum...@odiso.com> Cc: pve-devel@pve.proxmox.com Envoyé: Lundi 6 Mai 2013 06:43:09 Objet: RE: PVE::Storage::volume_has_feature See my example ('copy' qcow2 snapshot while VM is running). I thought it is dangerous to access a qcow2 snapshot while the file is in use? > -----Original Message----- > From: Alexandre DERUMIER [mailto:aderum...@odiso.com] > Sent: Montag, 06. Mai 2013 06:41 > To: Dietmar Maurer > Cc: pve-devel@pve.proxmox.com > Subject: Re: PVE::Storage::volume_has_feature > > Yes, Currently I don't use use it, because I think we can do snapshots,full > clone, > linked cloned online or offline for each storage. > > Do you see a storage with a feature available offline and not online by > example > ? > > ----- Mail original ----- > > De: "Dietmar Maurer" <diet...@proxmox.com> > À: "Alexandre DERUMIER (aderum...@odiso.com)" <aderum...@odiso.com> > apsho > Cc: pve-devel@pve.proxmox.com > Envoyé: Lundi 6 Mai 2013 06:24:05 > Objet: PVE::Storage::volume_has_feature > > That function seems to ignore the 'running'parameter, for example: > > --------test code------ > #!/usr/bin/perl -w > > use strict; > use PVE::Storage; > > my $volid = "local:200/vm-200-disk-1.qcow2"; my $snapname = "firstboot"; my > $runnung = 1; > > my $storecfg = PVE::Storage::config(); > > die "got unexpected result" if PVE::Storage::volume_has_feature($storecfg, > 'copy', $volid, $snapname, 1);; > > ----- end test code--------- > > how can we fix that? _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel _______________________________________________ pve-devel mailing list pve-devel@pve.proxmox.com http://pve.proxmox.com/cgi-bin/mailman/listinfo/pve-devel
