Lenny Dom0 guest console hangs at boot.

When you attempt to boot a Xen DomU on Debian Lenny Dom0, the console might hang as the follows:

Starting NFS servers: nfsd mountd.
Starting automounter: amd.
Starting anac(h)ronistic cron: anacron.
Starting periodic command scheduler: crond.
Running local boot scripts (/etc/rc.local).

This problem occurs when using xen-tools to create a new (Debian Lenny in my case) guest image and configuration.

The cause for the problem is when the guest configuration file does not have the “extra” configured.
To solve this problem – just add -

extra = ‘console=hvc0 xencons=tty

To your guest configuration file.

kernel = '/boot/vmlinuz-'
ramdisk = '/boot/initrd.img-'
extra = ‘console=hvc0 xencons=tty
memory = '512'
root = '/dev/sda2 ro'
disk = [
name = 'vm01'
vif = [ 'mac=00:16:7E:DC:C9:F6' ]
on_poweroff = 'destroy'
on_reboot = 'restart'
on_crash = 'restart'

If you are using pygrub, edit /boot/grub/menu.lst  on the domU and append -  console=hvc0 xencons=tty to the kernel line.

Project Remus

Remus provides transparent, comprehensive high availability to ordinary virtual machines running on the Xen virtual machine monitor. It does this by maintaining a completely up-to-date copy of a running VM on a backup server, which automatically activates if the primary server fails. Key features:

* The backup VM is an exact copy of the primary VM. When failure happens, it continues running on the backup host as if failure had never occurred.
* The backup is completely up-to-date. Even active TCP sessions are maintained without interruption.
* Protection is transparent. Existing guests can be protected without modifying them in any way.

For more details:


Vyatta Virtualized – Xen images

I have found this post at the Vyatta users forum.

I wanted to let everyone know that I have posted a number of Vyatta images for different virtualization platforms. Please feel free to test them out and let me know how they work for you.

I have built a template for CItrix XenServer using XenServer5. This template includes a paravirtualized kernel so it should work on non-VT enabled processors and should be significantly faster than an HVM image. It does not yet support Xen tools. Xen tools support requires /proc/xen which is first introduced in linux 2.6.29. I am in the process of porting this beta kernel over to Vyatta. When that is done, I will produce a second Cirix image that includes Xen tools. The image for Citrix XenServer is located at:


I have also posted an image for the open source version of Xen. This image is also paravirtualized. The Vyatta image and a template for a cfg are located here:


Xen Virtualization Support And How To's