On Mon, Jun 10, 2013 at 12:04:24PM -0400, Cole Robinson wrote: > On 06/09/2013 01:07 PM, Pasi Kärkkäinen wrote: > > Hello, > > > > Does anyone know where/how to set the default libvirt Xen blktap "driver name" for disk image files? > > > > If I have "blktap" module loaded in dom0 kernel, and I do this: > > > > virt-install -d -n blktaptest01 -r 2048 --vcpus=2 --disk /var/lib/libvirt/images/blktaptest01.img,size=8 --vnc -p -l "http://ftp.funet.fi/pub/mirrors/centos.org/6.4/os/x86_64"; > > > > which results in this generated libvirt xml config for the VM: > > > > <disk type='file' device='disk'> > > <driver name='tap' type='aio'/> > > <source file='/var/lib/libvirt/images/blktaptest01.img'/> > > <target dev='xvda' bus='xen'/> > > </disk> > > > > .. which doesn't seem to work for me with Xen 4.2.2 using xm/xend, and libvirt 0.10.x. > > > > The problem is there's no tapdisk process started in dom0, and the block device cannot be > > initialized or accessed inside the VM. I have the same problem with virt-manager, > > using the "new VM" wizard with disk image files. > > > > The correct "driver name" for libvirt is "tap2", which works for me, > > so I need to manually edit the libvirt xml config to make the VM boot/work: > > > > <disk type='file' device='disk'> > > <driver name='tap2' type='aio'/> > > <source file='/var/lib/libvirt/images/blktaptest01.img'/> > > <target dev='xvda' bus='xen'/> > > </disk> > > > > This matches xm/xend behaviour with text config files for VMs. > > I need to use tap2 there aswell on the disk = [] line. > > > > Where should I choose/set/patch the default libvirt driver name? Is that in libvirt sources, > > or in virt-install/virt-manager ? I tried reading the libvirt "xen" driver source, > > but I couldn't find any "default" setting there.. > > > > Hmm. This is old old behavior in virtinst. If the blktap module is loaded on > the local host we use the 'tap' driver. > Yep, I noticed, removing "blktap" resulted in different behaviour (using the file: driver). > According to the libvirt log, tap2 has been available since xen 4.0, so > virtinst should probably check if xen >= 4.0 and libvirt >= 0.9.7, which is > the first libvirt version where it sounds like tap2 is usable. This would be a > check in virtinst/support.py > Ok. Does virt-manager also use virtinst internally? Or do I need to separately patch virt-manager ? > You should also be able to manually work around it by doing --disk > ...,driver_name=tap2,driver_type=aio > Yep, that works, but I'm kind of trying to figure out how to make the default behaviour correct. Thanks! -- Pasi _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
