[fedora-virt] How to use virtio-scsi on F17 host and F17 guest

[Cole Robinson]

On 06/07/2012 09:48 AM, Gianluca Cecchi wrote:
> On Thu, Jun 7, 2012 at 3:25 PM, Cole Robinson wrote:
>> It looks like you want to add :
>>
>> <controller type='scsi' index='0' model='virtio-scsi'/>
>>
>> Then in change that <target line to
>>
>> <target dev='sda' bus='scsi'/>
>>
>> Problem is this will change the disk device node in the guest from vda to sda,
>> so could cause mounting problems.
>>
>> - Cole
> 
> Actually, at least in F17, both the kernel command line "root=..."
> part and the device first column in fstab refer to UUID...
> So I think it should be transparent for the guest os, as far as inside
> the standard initrd there is the virtio_scsi.ko kernel module
> available.
> And it seems it is so:
> $ gunzip < /boot/initramfs-3.3.7-1.fc17.x86_64.img | cpio -itdmv |
> grep virtio_scsi
> -rwxr--r--   1 root     root        16144 May 22 00:42
> usr/lib/modules/3.3.7-1.fc17.x86_64/kernel/drivers/scsi/virtio_scsi.ko
> 
> current config
> <disk type='file' device='disk'>
>      <driver name='qemu' type='qcow2'/>
>      <source file='/var/lib/libvirt/images/f17.img'/>
>      <target dev='vda' bus='virtio'/>
>      <address type='pci' domain='0x0000' bus='0x00' slot='0x06'
> function='0x0'/>
>    </disk>
> 
> would then become
> <disk type='file' device='disk'>
>      <driver name='qemu' type='qcow2'/>
>      <source file='/var/lib/libvirt/images/f17.img'/>
>      <target dev='sda' bus='scsi'/>
>    </disk>
> 
> What about
>      <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/>
> ?
> Cut out?
> 
> And after adding
> <controller type='scsi' index='0' model='virtio-scsi'/>
> can I cut out the
>     <controller type='virtio-serial' index='0'>
>       <address type='pci' domain='0x0000' bus='0x00' slot='0x05'
> function='0x0'/>
>     </controller>
> 
> that I think is for current virtio_blk disk ?
> 

Nope, that's something different, so keep that. But do drop the <address
type='pci'... line from the <disk> block, and libvirt will generate you a new one.

- Cole