Finally bit the bullet and upgraded my rock stable Mageia 4 installation to Mageia 5.
This is my 'main" box, mythtv backend w/tuners etc, 3 monitors driven by a 2GB ATI 6950
2 raid arrays: /home is on a 1tb raid1, 1gb, /video (mythtv recordings etc) on a 2tb raid0.
After the regular installers choked, I tried an online update via urpmi, which was ~fast but failed installing the new kernel, fortunately the mga4 ones still worked. (digging revealed grub installation was failing with RAID related errors)
On the upgraded MGA5 or from Live DVD, the arrays are apparently no longer started automatically on boot?
(this setup has worked before Mageia existed on Mandriva, then MGA1/2/3/4 with no issues.)
If I run "''dmraid -ay" it finds everything, then "mount -av" mounts everything fine.
THEN I can log into X11 per usual.
Live DVD installer or mccs disk manager both died after popping up a window until "dmraid -ay" was done.
(did not want a clean install from Live DVD as i wanted to save 30 minutes setting up mysql and mythtv, which worked otherwise, I typically do a clean install of OS)
See
viewtopic.php?f=8&t=10326 for thread, by request