Oh, sorry, had this on my todo list and somehow missed it. This looks ok, in my case read-only device is not part of migrate-disks parameter, so everything should be all right. Thanks for testing it! Kind Regards, Pawel Koniszewski > -----Original Message----- > From: Jason J. Herne [mailto:jjherne@xxxxxxxxxxxxxxxxxx] > Sent: Thursday, August 25, 2016 3:22 PM > To: Corey S McQuay <csmcquay@xxxxxxxxxxxxxxxxxx>; Koniszewski, Pawel > <pawel.koniszewski@xxxxxxxxx>; libvir-list@xxxxxxxxxx > Subject: Re: [PATCH v1] qemu-migration: Disallow migration of read > only disk > > On 08/17/2016 05:10 PM, Jason J. Herne wrote: > > On 08/11/2016 08:57 AM, Corey S McQuay wrote: > >> On 08/10/2016 09:16 AM, Koniszewski, Pawel wrote: > >> > >>>> -----Original Message----- > >>>> From: libvir-list-bounces@xxxxxxxxxx [mailto:libvir-list- > >>>> bounces@xxxxxxxxxx] On Behalf Of Corey S. McQuay > >>>> Sent: Friday, August 5, 2016 8:34 PM > >>>> To: jjherne@xxxxxxxxxxxxxxxxxx; libvir-list@xxxxxxxxxx > >>>> Cc: Corey S. McQuay <csmcquay@xxxxxxxxxxxxxxxxxx> > >>>> Subject: [PATCH v1] qemu-migration: Disallow migration of > >>>> read only disk > >>>> > >>>> From: "Corey S. McQuay" <csmcquay@xxxxxxxxxxxxxxxxxx> > >>>> > >>>> Currently Libvirt allows attempts to migrate read only disks. Qemu > >>>> cannot handle this as read only disks cannot be written to on the > >>>> destination system. > >>>> The end result is a cryptic error message and a failed migration. > >>>> > >>>> This patch causes migration to fail earlier and provides a > >>>> meaningful error message stating that migrating read only disks is > >>>> not supported. > >>> What will happen if read-only disk is copied to destination prior to > >>> migration start? Currently such scenario works, will it still work > >>> with this code? > >> Based on our testing, pre-copying a read only disk image to the > >> destination system has no effect on the outcome of attempting to > >> migrate a non-shared read only disk. I'm not sure what scenario you > >> are referring to but here is what we tried: > >> > >> Relevant guest xml: > >> <disk type='file' device='cdrom'> > >> <driver name='qemu' type='raw' cache='writethrough'/> > >> <source file='/disk-images/guest.iso'/> > >> <backingStore/> > >> <target dev='sdz' bus='scsi'/> > >> <readonly/> > >> <alias name='scsi0-0-0-0'/> > >> <address type='drive' controller='0' bus='0' target='0' unit='0'/> > >> </disk> > >> > >> The disk image exists at /disk-images/guest.iso on the source. Before > >> migration we copied the image to the same path on the destination > >> system. Then we attempted migration: > >> > >> virsh migrate --live --copy-storage-all --migrate-disks sdz > >> --verbose kvm1 qemu+ssh://dstHost/system tcp://dstHost > >> > >> The error message we get is: > >> > >> error: internal error: info migration reply was missing return status > >> > >> Running journalctl shows additional information: > >> > >> Aug 10 16:02:16 collin-kvm libvirtd[41616]: operation failed: > >> migration of disk sdz failed. > >> > >> I'm pretty sure this patch does not stop the user from doing anything > >> that works today. But if your scenario is different from ours in some > >> way please let us know and we'll do some more testing. > > > > Pawel, > > > > Thanks for taking a look. Does Corey's reply address your concerns? > > > > Polite ping for Pawel, and anyone else who wants to review. Thanks :) > > Original patch here: > https://www.redhat.com/archives/libvir-list/2016-August/msg00378.html > > -- > -- Jason J. Herne (jjherne@xxxxxxxxxxxxxxxxxx) -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list