[libvirt-users] Dual-boot and also use raw disk in virtual machine

[Justin Clift]

On 06/07/2010 04:22 PM, Richard Walker wrote:
> On 7 June 2010 14:59, Justin Clift<justin at salasaga.org>  wrote:
>> On 06/07/2010 02:39 PM, Richard Walker wrote:
>> <snip>
>>>
>>> And at last . . . success!
>>
>> Interesting.  Hope you've taken a backup (image the hdd or something). :)
>
> Uh, yes, well, maybe I will get around to that.
>
> The next problem to face is activation.
> Having activated the native install, now I have three
> days to activate in the VM, and that doesn't work.
> Too many hardware "changes" I suppose . . .

Btw, the snapshot approach mentioned works.  It's very easy.

For a 500GB physical disk, with an OS installed on it:

   # qemu-img create -f qcow2 -o 
backing_file=/dev/sdb,backing_fmt=host_device 
/home/images/sdbimagesnap2.qcow2 500G

That creates the snapshot.  Then change a guest XML file to point to the 
snapshot.  From:

   <disk type='block' device='disk'>
     <driver name='qemu'/>            <-- no "type" here
     <source dev='/dev/sdb'/>         <-- physical device here
     <target dev='hda' bus='ide'/>
   </disk>

To:

   <disk type='block' device='disk'>
     <driver name='qemu' type='qcow2'/>               <-- qcow2 type here
     <source dev='/home/images/sdbimagesnap2.qcow2'/> <--snapshot file
     <target dev='hda' bus='ide'/>
   </disk>

And the guest then uses the snapshot file, making writes only to that 
and leaving the physical device alone.

It probably would have been a good way to experiment with your dual boot 
solution, without invalidating the license keys when physically booting 
Windows.  Though, booting windows for real would likely silently corrupt 
the vm snapshots. :/

Good luck with your pursuit though.  Hope you figure the license 
activation thing out.  :)

Regards and best wishes,

Justin Clift

-- 
Salasaga  -  Open Source eLearning IDE
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