From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dustin Kirkland Subject: Re: [libvirt] dynamic scsi disk attach seems to be broken in qemu(-kvm)-0.11, libvirt-0.7.1 Date: Fri, 9 Oct 2009 10:38:17 -0500 Message-ID: References: <20091009081822.GB27937@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: libvir-list@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org To: "Daniel P. Berrange" Return-path: In-Reply-To: <20091009081822.GB27937@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: libvir-list-bounces@redhat.com Errors-To: libvir-list-bounces@redhat.com List-Id: kvm.vger.kernel.org On Fri, Oct 9, 2009 at 3:18 AM, Daniel P. Berrange = wrote: > On Thu, Oct 08, 2009 at 10:57:55PM -0500, Dustin Kirkland wrote: >> Now, all of that said, it is actually possible to hot-add a second >> scsi device. However, as far as I can tell, this method is not yet >> supported by libvirt. =A0It looks to me that with modern qemu, you hav= e >> to do it this way: >> >> Drop to a qemu console with ctrl-alt-2. Get the address of the current= scsi bus: >> =A0 (qemu) info pci >> =A0 Look for "SCSI Controller". In my case, it's on Bus 0, device 4, f= unction 0 >> >> Now instead of pci_add, use drive_add >> =A0 (qemu) drive_add 0:4 file=3D/tmp/foo,if=3Dscsi >> =A0 OK bus 0, unit 1 > > That is correct - the SCSI driver hotplug in libvirt is not implemented > in the right way. If you specify multiple SCSI devices at boot, they > all get on one controller, if you hotplug multiple SCSI devices, we're > hotplugging a new SCSI controller per disk. This is clearly not good, > because when you then reboot, all those controllers are merged back int= o > one. Okay, in our previous usage of this, rebooting didn't matter very much. > There is a guy who is working on implementing the correct SCSI hotplug > approach for libvirt, that is still work in progress though. The most > recent patches were here: > > http://www.redhat.com/archives/libvir-list/2009-September/msg00551.html > > We will ultimately support hotplug of both drives, and drive controller= s > independantly, giving apps/users the flexibility they need. Thanks. I'll track those patches with interest. :-Dustin