From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MwHY1-0004yf-2I for qemu-devel@nongnu.org; Fri, 09 Oct 2009 11:38:25 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MwHXw-0004su-4N for qemu-devel@nongnu.org; Fri, 09 Oct 2009 11:38:24 -0400 Received: from [199.232.76.173] (port=45823 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MwHXw-0004sm-0M for qemu-devel@nongnu.org; Fri, 09 Oct 2009 11:38:20 -0400 Received: from mail-bw0-f211.google.com ([209.85.218.211]:44059) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MwHXv-0000Zt-1v for qemu-devel@nongnu.org; Fri, 09 Oct 2009 11:38:19 -0400 Received: by bwz7 with SMTP id 7so1971482bwz.34 for ; Fri, 09 Oct 2009 08:38:17 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20091009081822.GB27937@redhat.com> References: <20091009081822.GB27937@redhat.com> Date: Fri, 9 Oct 2009 10:38:17 -0500 Message-ID: From: Dustin Kirkland Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Subject: [Qemu-devel] Re: [libvirt] dynamic scsi disk attach seems to be broken in qemu(-kvm)-0.11, libvirt-0.7.1 List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: libvir-list@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org On Fri, Oct 9, 2009 at 3:18 AM, Daniel P. Berrange wr= ote: > 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 have >> to do it this way: >> >> Drop to a qemu console with ctrl-alt-2. Get the address of the current s= csi bus: >> =A0 (qemu) info pci >> =A0 Look for "SCSI Controller". In my case, it's on Bus 0, device 4, fun= ction 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 into > 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 controllers > independantly, giving apps/users the flexibility they need. Thanks. I'll track those patches with interest. :-Dustin