[Libguestfs] Migrating file based Xen RHEL5.4 to KVM

[Martin Jeppesen]

> No, it's way more complex than that in virt-v2v.  "yum install kernel"
> runs /sbin/new-kernel-pkg which (eventually) runs plain mkinitrd.
> Unfortunately that just makes an initrd suitable for the current
> (ie. pre-migration) hardware.
>
> What you have to do is to run mkinitrd with all the right parameters
> (by examining /sbin/new-kernel-pkg by hand) plus some extra parameters
> to install the virtio drivers, something like 'mkinitrd --preload=virtio_blk
> [...]'.  You need at least the block driver in order to boot, and
> after booting you should probably run /sbin/new-kernel-pkg again.
>
> IMHO it would be better for the kernel to ship with a standard initrd
> that does everything possible.  dracut was meant to solve these
> issues, but in reality it's just a much slower replacement for
> mkinitrd.  (Also they should have just used Debian's initramfs.)

Very interesting!

> Anyway, I'd suggest you use virt-v2v.  It supports file-based guests
> just fine.

Ahh. Now I see how it works. The migration is done entirely on the KVM
host when the guest is offline.

So I have actually the Xen guest locally on the KVM host connected
through the libvirt. Which is why I just can give virt-v2v the domain?

Thanks a bunch.