Xen users - Dec 2012 - Accessing individual partitions of a HVM guest

Hi,

I need to do some p2v migration of a very old SuSE server.
Unfortunately, the kernel of that machine doesn''t support running as
xen
domU, so I need to put the machine into a HVM domU.

When I set up the domU with

   disk = [''phy:/dev/vg_guest/worker1_disk,sda1,w'']

then the domU doesn''t boot because it says that no OS was found on the
HDD.

Of course I could set up the domU with

   disk = [''phy:/dev/vg_guest/worker1_disk,sda,w'']

but then how can I access the individual partitions of the domU''s
/dev/sda from the dom0?

I believe I need to do this because I need to somehow rsync the
machine''s data to the new host, and I thought that this would be done
by
calling rsync from the dom0 and writing to the target partition.
However, how do I set up this target disk?

I''m at a loss here -- your help is greatly appreciated!

Cheers, Andreas.

On 27.12.2012 18:40, Andreas Hilboll wrote:
> I need to do some p2v migration of a very old SuSE server.
> Unfortunately, the kernel of that machine doesn''t support running
as xen
> domU, so I need to put the machine into a HVM domU.
> 
> When I set up the domU with
> 
>    disk = [''phy:/dev/vg_guest/worker1_disk,sda1,w'']
> 
> then the domU doesn''t boot because it says that no OS was found on
the HDD.
> 
> Of course I could set up the domU with
> 
>    disk = [''phy:/dev/vg_guest/worker1_disk,sda,w'']
> 
> but then how can I access the individual partitions of the domU''s
> /dev/sda from the dom0?
kpartx


Greetings,

Paul

Hello.

El 27/12/12 11:40, Andreas Hilboll escribió:
> I need to do some p2v migration of a very old SuSE server.
> Unfortunately, the kernel of that machine doesn''t support running
as xen
> domU, so I need to put the machine into a HVM domU.
>  [...]
> but then how can I access the individual partitions of the domU''s
> /dev/sda from the dom0?
kpartx is the tool. It will create device files under /dev/mapper for 
each partition it finds on the block device you give it. Do not forget 
to unmap the partitions after you done.

Another way is to mount your /dev/vg_guest/worker1_disk as is, with 
"mount -o offset=XYZ ". Needs no mapping additional tools, but
it''s tricky.

-- 
Alexandre Kouznetsov

>> I need to do some p2v migration of a very old SuSE server.
>> Unfortunately, the kernel of that machine doesn''t support
running as xen
>> domU, so I need to put the machine into a HVM domU.
>>
>> When I set up the domU with
>>
>>    disk = [''phy:/dev/vg_guest/worker1_disk,sda1,w'']
>>
>> then the domU doesn''t boot because it says that no OS was
found on the HDD.
>>
>> Of course I could set up the domU with
>>
>>    disk = [''phy:/dev/vg_guest/worker1_disk,sda,w'']
>>
>> but then how can I access the individual partitions of the
domU''s
>> /dev/sda from the dom0?
> 
> kpartx
Thanks, guys, works like a charm :)

Cheers, Andreas.