[Fedora-xen] 3 failed approaches to create guest domains

[Olivier Renault]

Siddharth Wagh wrote:
> Hello all,
> 
> I am a Masters student working on my thesis and have to go use Xen for 
> live migration purposes. I have a Xen installation on Fedora 8, and been 
> trying for past 3 months to create guest domains and get them running 
> for further migration work. I took 3 different approaches, but got stuck 
> with each of those. I would be very grateful if you could point out as 
> to where I am going wrong...
> *
> 1. Basic command:
> xm create -c vm01-config.sxp vmid=1*
> 
> The config file is kept in /etc/xen folder.
> 
> ERROR:
> VFS: Cannot open root device "hd0" or unknown-block(0,0)
> Please append a correct "root=" boot option
> Kernel panic - not syncing: VFS: Unable to mount root fs on 
> unknown-block(0,0)
> 
> WHAT I PUT IN:
> root = '/dev/hd0' or '/dev/hda' or '/dev/sda2'
> 
> None worked. I am not sure what the option should be.
> 
> *
> 2. Using the command:
> virt-install -f /etc/xen/xen1 -r 256*
> 
> WHAT IT DOES:
> Asks for config parameters and creates virtual machine, but I am not 
> sure how to proceed with completion process. In the install location, I 
> put in a  OS image at a mirror site:
> 
> http://ringtail.its.monash.edu.au/pub/fedora/linux/releases/8/Fedora/i386/os/
> 
> ERROR:
> Unable to find image at given location
> 
> This is the only approach which creates a VM, but the machine is not 
> completely running (not functional or doesnt consume any memory). Am I 
> supposed to have the guest image on my machine?
> 
> 
> *3. Using "virt-manager" in GUI*
> 
> ERROR: Asks for "Connect to host  network" *but "shared physical 
> devices" list is empty*. It is supposed to list eth0, peth0 etc. 
> Something to do with creating a bridge. I tried the approach of NAT, but 
> for that I have to use approach 1 to create a machine, which gets stuck 
> on "root" error.
> 
> 
> Libvirtd is not running. It gave the message:
> 
> libvir: Remote error : Connection refused
> libvir: warning : Failed to find the network: Is the daemon running ?
> libvir: Remote error : Connection refused
> 
> xend is running, I checked status.
> 
Commenting on method 2:

If you have got a iso of F8 DVD somewhere, mount it loopback on 
/var/www/html/pub & start your web server

# mount -o loop F8.iso /var/www/html/pub
# service httpd start

Then you should be able to do the installation

          # virt-install \
               --paravirt \
               --name demo \
               --ram 500 \
               --file /var/lib/xen/images/demo.img \
               --file-size 6 \
               --nographics \
               --location http://ip of your web server/pub


Good luck.
Olivier