FC6: pvmove gives "device-mapper: reload ioctl failed: Invalid argument"

Hi,
I had exactly the same problem. My guess is that it has something to do with the device-mapper not getting along with the x86_64 kernel.

This is how I proceeded:
1) booted knoppix
2) loaded the dm-mod, and the dm-mirror modules:
modprobe dm-mod
modprobe dm-mirror
3) pvmove /dev/sddc1 ... and so on

seems to work fine,
~caleb