On Wed, Nov 17, 2010 at 06:04:50PM -0800, Josh Durgin wrote: > On 11/17/2010 04:33 PM, Josh Durgin wrote: > >Hi Daniel, > > > >On 11/08/2010 05:16 AM, Daniel P. Berrange wrote: > >>>>>In any case, before someone goes off and implements something, does > >>>>>this > >>>>>look like the right general approach to adding rbd support to libvirt? > >>>> > >>>>I think this looks reasonable. I'd be inclined to get the storage pool > >>>>stuff working with the kernel RBD driver& UDEV rules for stable path > >>>>names, since that avoids needing to make any changes to guest XML > >>>>format. Support for QEMU with the native librados CEPH driver could > >>>>be added as a second patch. > >>> > >>>Okay, that sounds reasonable. Supporting the QEMU librados driver is > >>>definitely something we want to target, though, and seems to be route > >>>that > >>>more users are interested in. Is defining the XML syntax for a guest VM > >>>something we can discuss now as well? > >>> > >>>(BTW this is biting NBD users too. Presumably the guest VM XML should > >>>look similar? > >> > >>And also Sheepdog storage volumes. To define a syntax for all these we > >>need > >>to determine what configuration metadata is required at a per-VM level > >>for > >>each of them. Then try and decide how to represent that in the guest XML. > >>It looks like at a VM level we'd need a hostname, port number and a > >>volume > >>name (or path). > > > >It looks like that's what Sheepdog needs from the patch that was > >submitted earlier today. For RBD, we would want to allow multiple hosts, > >and specify the pool and image name when the QEMU librados driver is > >used, e.g.: > > > ><disk type="rbd" device="disk"> > ><driver name="qemu" type="raw" /> > ><source vdi="image_name" pool="pool_name"> > ><host name="mon1.example.org" port="6000"> > ><host name="mon2.example.org" port="6000"> > ><host name="mon3.example.org" port="6000"> > ></source> > ><target dev="vda" bus="virtio" /> > ></disk> > > > >As you mentioned earlier, we could just use the existing source format > >for the kernel RBD driver. > > > >Does this seem like a reasonable format for the VM XML? Any suggestions? > > Also, it would be convenient to be able to specify which RBD driver to > use in the guest XML, so that it's independent of the libvirt pool > configuration. Would having two different rbd disk types be the right > approach here? What do you mean by RBD driver here ? kernel vs native QEMU ? If so, the kernel case is trivially handled by the <disk type='block'> case, so we only need new syntax for the native QEMU impl Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :| -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list