We've exported some VMs from our old oVirt infrastructure and want to import them into the new one, but qemu-img appears to be failing. We have mounted an export domain populated from the old oVirt in the new hosted engine and are using the GUI to import the VM. Manually running the command sits at 16% CPU, 0% network usage and no progress. It appears to lock the NFS mount and ls and lsof both hang.

sudo -u vdsm /usr/bin/qemu-img convert -p -t none -T none -f raw <path to source> -O raw <path to dest>

Conversely a simple cp will work (ruling out file permissions errors):

sudo -u vddm cp <path to source> <path to test>

What might we be doing wrong?