I've been asked to downgrade an AIX system to 4.15r2. Whilst I'm not
at
all familiar with AIX, I'm guessing that the easiest way to do this
will
be to wipe the hard disk and install the older version from scratch. I
understand that to do this, I must boot the from the installation CD.
Unfortunately I can't figure out how to do this!

After the POST sequence, I can hit <ESC> to bypass AutoBoot, at which
point I have the opportunity to select an alternate boot device. I am
then prompted in turn for the Controller, Drive, Partition and File
that
I wish to boot from.

In order to find out which values I should enter, I booted into the
existing installation and typed "lscfg -up -lcd0". This tells me that
the CD-ROM drive is at location "04-C0-00-5,0" - but nowhere can I find
what this actually means! I guessed that perhaps '5' was the
drive number and that the controller and partition values were 0, but
attempting to boot from this failed ("Boot Logic Error - Packet Status
300").

I have also tried pressing 5 repeatedly during bootup, to no avail. I
successfully changed the boot order to try the CD first using "bootlist
-m normal cd0 hdisk0", but it proceeded to boot from the hard disk as
normal. I'm unsure of the exact hardware version, but it isn't old
enough to have a "service" mode (or a key).

Does anybody know what "04-C0-00-5,0" means? Or are there any other
suggestions on how to boot from the CD? Is there anyway of verifying
that the installation CD is actually bootable?

TIA,

Jon
PS: We may be looking for some kind of email or telephone support
contract shortly, so if anybody has any recommendations, please let me
know.

Jon,

Setting the boot list to "cd0 hdisk0" as you have done, *is* the
correct way of doing it. You should see the CD light blinking at boot
time. If it doesn't work, then you either have a duff AIX CD or
(especially for systems *after* the RS/6000 divide), your system isn't
supported on AIX 4.1.5. For a version that old, you should be trying
this on an RS/6000 43P, an F50 or something else in that age range. As
far as gerontophilia is concerned, the strangest thing I ever did was
install AIX 4.3.2 on an e-Server P615. I did that over the network
using a NIM server because the installation media was too old.

The "04-C0-00-5,0" is a location code for a device. It depends on the
particular system what it actually means, but it is usually a function
of the sysplanar, the bus and the device ID on that bus.

If you have another AIX box sitting there, install a NIM server on it,
create an LPPsource and a SPOT for AIX 4.1.5 and try to install it over
the network. Added benefit: No CDs to shuttle and typically a lot
faster.

I don't know if you want to go Blue for your support, but you'll have
a hard time getting IBM to talk about pre-5.1 versions of AIX.

Hope this helps,


Cheers,
Menno Willemse

Jonathan Melhuish schrieb:
> I've been asked to downgrade an AIX system to 4.15r2.

There was no 4.15r2.
4.1.5 Maintenancelevel 01.
Microchannel or PreP machines only.
4.1.5 has not support for CHRP machines. So every machine that can run
5.2 or 5.3 will never boot 4.1.5.
If it has a black case -> no chance.

The very first AIX supporting the first CHRP machines was 4.2.1.

--
Uli