Power 7 CentOS ppc64 install disk boots but "No disks detected"

Woohoo!

Managed to boot CentOS ppc64
<https://wiki.centos.org/SpecialInterestGroup/AltArch/ppc64> (it's
big-endian) installation disk on P7! Comes up in serial terminal!

Only required about 4 days' research, building cables, trial and error and
error and error ... :)

Big trick: ASMI -> Power/Restart Control -> Power On/Off System -> Default
Partition Environment: *Linux*

*BUT* ("Everyone's got a big 'but'." - Peewee Herman, "Peewee's Big
Adventure") ...

Installation

1) [x] Language settings 2) [!] Time settings
(English (United States)) (Timezone is not set.)
3) [x] Installation source 4) [x] Software selection
(Local media) (Minimal Install)
5) [!] Installation Destination 6) [x] Kdump
(No disks selected) (Kdump is enabled)
7) [ ] Network configuration 8) [!] Root password
(Not connected) (Password is not set.)
9) [!] User creation
(No user will be created)
Please make your choice from above ['q' to quit | 'b' to begin installation |
'r' to refresh]: 5
================================================================================
================================================================================
Probing storage...
Installation Destination
No disks detected. Please shut down the computer, connect at least
one disk,and restart to complete installation.

Please make your choice from above ['q' to quit | 'c' to continue |
'r' to refresh]: r

I wonder if it doesn't like the funny-sector IBM i DASD?

Or do I have to do some config magic with the system down to add the disks
so CentOS install can see them?

I did do a "reset to factory defaults" at one point. Did I lose my DASD? Or
is it something else?

The DASD lights all flash quite a bit during the CentOS install DVD bootup
so I do think it's looking at 'em.

Thanks for any pointers!