[CentOS-virt] Vmware Server 2 and KVM....

James Hogarth james.hogarth at gmail.com
Mon Aug 16 11:36:13 EDT 2010

On 16 August 2010 16:22, Tom Bishop <bishoptf at gmail.com> wrote:
> "I put together a simple conversion method I used at work to move from
> vmware to KVM - happy t opost the instructions if needed."
> That would be good I have read several things but would be nice to see.....
> I'm not sure how much vmware server 2 makes use of the hardware extensions
> but thought I would give it a try and see what happens....

No problem - I'm at home today but in the office tomorrow. I'll post
my specific steps I documented then... but approximately from

1. Make sure the vmware disk has no snapshots and is a 'full disk'
2. Convert the vmdk to a raw image (or qcow2... or even leave as vmdk
dependant on your needs and performance issues) using qemu-img.
3. Construct an XML template for the new kvm guest and import it with
virsh define.
4. Boot up from a CentOS live cd/dvd within the new kvm guest.
5. chroot into the disk within the guest.
6. remove vmware tools (if installed)
7. if using virtIO (advisable for performance) rebuild the initrd with
the virtio modules: mkinitrd --with=virtio_blk --with=virtio_pci
/boot/initrd.... <kernel_version>
8. change /boot/grub/device.map from /dev/sda to /dev/vda (assuming
changing to virtio).
9. exit the chroot
10. reboot system from the disk instead of the live cd/dvd and troubleshoot/test

You shouldn't have to reinstall grub but you can do that from in a
live CD via grub-install --root-directory=<mount_pount> /dev/vda if it
goes weird...

That's pretty much it from off teh top of my head including the change
from emulated (scsi|IDE) disks or (e1000|vmxnet) NICs etc over to
virtio equivalents for performance... Centos 5.4 and up have the
virtio modules natively for teh guest but they need an initrd with
them in to boot off at first.... hmm come to think of it you could do
that prior to shutting down and then skip the live CD/DVD step ... but
then you wouldn't be able to start cleanly back into the vmware
version rather than KVM if need be without a live CD/DVD for the grub
device.map file ... otherwise it will just get unknown disk (I think?)


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