On 06/10/2013 12:10 PM, Pasi Kärkkäinen wrote: > 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 ? > All the code is in the same repo and shared between virt-* tools. However 'git grep blktap' shows an instance in virtManager/addhardware.py where we are duplicating the check, so that would need to be handled as well. Thanks for looking into this! git clone git://git.fedorahosted.org/virt-manager.git - Cole _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
