W: GPG error: http://updates.vmd.citrix.com etch Release: The following signatures couldn’t be verified because the public key is not available: NO_PUBKEY 841D6D8DFE3F8BB2
W: You may want to run apt-get update to correct these problems

Issue the following command:

wget -q http://updates.vmd.citrix.com/XenServer/5.5.0/GPG-KEY -O- | apt-key add -

This will download the current gpg key from the citrix update server and add the key to apt. You should see an ok message after thats done run

aptitude update The error message should be gone

2. Uninstall vmware modules on the vmware guest you wish to convert

3. Stop the vmware guest

4. Convert the image file qemu-img convert Linux_2.6.x_kernel-flat.vmdk -O raw Debian.img

5. Copy the image file to the xen server with scp or ftp or to an attached storage server if you have one. Your storage uuid will be different: scp Debian.img 10.110.1.1:/var/run/sr-mount/7d327ac3-f85e-e742-1f5b-f52dd4dbadf6

6. Create a guest with at least the same disk size and amount of RAM as the imported vmware virtual disk. Rename the disk under properties so you can locate it later.
You may need to boot the guest with an ISO image to get it to work

7. Open a console or connect to the xen server with ssh and find the disk copy the uuid of the host: xe vdi-list or with: xe vdi-list name-label=your_disk_name

8. Import the image with: xe vdi-import uuid=652cc56f-4251-44d0-8f07-dcf219edf15a filename=Debian.img

9. Fire up your converted xen image. You may have to modify the grub boot loader vmware uses /dev/sda for it’s HD and xen uses /dev/hda.

10. If you machine does not boot press e at the grub prompt an search for root=/dev/sda1 line and change it to root=/dev/hda1 please change this in you grub.conf once the machine has booted and save your changes