Hi Konrad,

have tried now - but not with lvm (actually I have no lvm group here and 
I do not want to lvm one complete drive) but with direct assigning a 
partition. /dev/sdb is 80GB big.
two tries:
1st one:
virt-install --prompt
Would you like a fully virtualized guest (yes or no)? This will allow 
you to run unmodified operating systems. yes
  What is the name of your virtual machine? test
  How much RAM should be allocated (in megabytes)? 256
  What would you like to use as the disk (file path)? /dev/sdb3
  What is the install CD-ROM/ISO or URL? 
/home/GWAY-4.2.15-037-BarracudaNG.iso

Machine stuck, in qemu I could see after recognizing ata0 as 80GB qemu 
harddisc, after some time the ata1 as virtual DVD. again after some 
while I could see the iso bootscreen and machine was back until pressing 
enter for further booting.

2nd one: to avoid file-command for iso-file:
virt-install --prompt
Would you like a fully virtualized guest (yes or no)? This will allow 
you to run unmodified operating systems. yes
  What is the name of your virtual machine? test
  How much RAM should be allocated (in megabytes)? 256
  What would you like to use as the disk (file path)? /dev/sdb3
  What is the install CD-ROM/ISO or URL? 
http://mirrors.kernel.org/centos/5.6/os/x86_64/

After downloading boot-images machine stuck, in qemu I could see again 
ata0 as 80GB harddisc, after some time it tried to boot but could not 
find any bootable devices.

I've attached again xm dmesg and dom0 dmesg.

Thanks for your effords.

best regards
Alois

On 04/19/2011 03:28 PM, Konrad Rzeszutek Wilk wrote:
> On Tue, Apr 19, 2011 at 12:35:33AM +0200, MadLoisae@gmx.net wrote:
>    
>> I have to revise my last email.
>> Not only the initialisation is slow, also further I/O stalls the dom0.
>> This is an Intel 945GM/E chipset, with an IDE-CF-Card as / (ext3)
>> filesystem and an IDE-2.5" hardisk (/home, ext4). IDE-CF-card is
>> slower, only able to read/write about 35MBytes/second, the 2.5" HDD
>> is at about 55MBytes/sec.
>> Both, the ISO-image and the virtual harddisk are on the /home
>> directory and therefore on the harddisk.
>> Is there maybe an I/O problem? Dom0 is able to do everysth. like
>> usual on all filesystems, both disks are without errors.
>>      
> Perhaps? Not sure. Can you put your guest image on an LVM (logical
> volume) or a disk partition instead of a file?
>
>