Manually converting ova to qcow2 is not without issues...
> tar xvf MyAppliance.ova
> qemu-img convert -O qcow2 MyAppliance-disk1.vmdk MyAppliance.qcow2
Doesn't work and KVM/qemu machine boot falls into Dracut Emergency Shell
> Starting Dracut Emergency Shell...
> Warning: /dev/centos/root does not exist
> Warning: /dev/centos/swap does not exist
> Warning: /dev/mapper/centos-root does not exist
>
> Generating "/run/initramfs/rdsosreport.txt"
>
> Entering emergency mode. Exit the shell to continue.
> Type "journalctl" to view system logs.
> You might want to save "/run/initramfs/rdsosreport.txt" to a USB stick or /boot
> after mounting them and attach it to a bug report.