Migrate Xen to KVM on RHEL/CentOS 6

http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Virtua...
Follow suggestion: Instead of turning off NetworkManager, add "NM_CONTROLLED=no" to the ifcfg-* scripts used in the examples.
In my experience it was necessary to have the following lines in ifcfg-br0 (replacing .4. as required)
BROADCAST=192.168.4.255 NETMASK=255.255.255.0 NETWORK=192.168.4.0
It is also necessary to disable network manager or the network will have to be restarted by hand every time the system is booted

create an xml file on the xen server with: virsh dumpxml > vm_name.xml
Create a disk image file of exactly the same name that the LV will have
edit the xml file and in the disk section change the lines
driver name='phy' to name='file' type='raw'
source dev='name of old lV' to source dev='new disk image file'
optionally change the MAC address (and this will also have to be changed in /etc/sysconfig/network-scripts/ifcfg-eth0
Now create the VM: (lvm_cdrive is the LVM pool you have created)
virt-v2v -i libvirtxml -op lvm_cdrive --bridge br0 www.xml
If a logical volume is created with a virt tool, it is important to use the tool to delete it.

If the MAC address has been changed so that both the new and old machines can be running at the same time, directories in the new machine (that have changed since imaging) can be updated from the old with rsync:
RSDIR=/etc RSREMOTE=www RSOPT="--archive -v --delete --compress --sparse --stats --progress --rsh=ssh" rsync $RSOPT root@$RSREMOTE:$RSDIR/ $RSDIR