[CentOS] Kickstarting CentOS 7 VM on CentOS 6 not possible?

Hi,

On CentOS 6.7 (all updates) kickstarting a CentOS 7 VM (in the way it
always has worked for other versions, incl. Fedora 22 VM's), does not
work for me.  I use virt-install with a local copy of the
"images/pxeboot" tree.  It all stops with:

    ...
    [  OK  ] Reached target Paths.
    [  OK  ] Reached target Basic System.
    dracut-initqueue[551]: Warning: Could not boot.
    dracut-initqueue[551]: Warning: /dev/root does not exist
             Starting Dracut Emergency Shell...
    Warning: /dev/root does not exist
    ...

I found zillion references to similar problems, including PXE-related
(I do not use PXE, but "-l" with virt-install) and cobbler-related
(no Cobbler involved), and I tried some of the suggestions, but none
of them worked.

Installing CentOS 7 "manually" using virt-install and the netboot ISO
works fine, but I want to use kickstart files.

Thanks for any suggestion.

-- 
--    Jos Vos <jos at xos.nl>
--    X/OS Experts in Open Systems BV   |   Phone: +31 20 6938364
--    Amsterdam, The Netherlands        |     Fax: +31 20 6948204