[Parted-maintainers] Bug#604134: ppc: after debian installation MacOS 9.2 won't recognize, disk anymore

[Sebastian Schroeer]

Dear Mr Wittau!

To make sure that nothing unexpected will cause you troubles, please 
read through my complete text first before doing anything: I 
successfully run Debian "Lenny", Mac OS 9, Mac OS X 10.4, and 10.5 on my 
PowerMac G4/800MHz "Quicksilver" using just one hard disk drive with 
various partitions. I can confirm that after an installation of Debian - 
Debian 5.0.7 "Lenny", but such problems also occured with a testing 
version of "Squeeze" I tested in August 2010 or so - on a NewWorld 
PowerPC Macintosh you might run into trouble booting a separate Mac OS 9 
OS from a different partition which you had installed before.

Please make sure that the program "Drive Setup", respectively "Laufwerke 
konfigurieren" (German system version of Mac OS 9) recognises the hard 
disk drive you use, for, actually, there are IDE HDDs which are not 
supported by this program, and then you cannot use it. As you intend to 
use yaboot I assume that the HDD is connected with an internal IDE port, 
i. e. the same hard disk drive(!) might cause troubles if you try to 
connect it via FireWire in an external case, for in many cases "Drive 
Setup" / "Laufwerke konfigurieren" will not recognize it anymore if 
connected externally via FireWire. (Problems regarding FireWire support 
of external hard disk drives and file systems were, however, fixed by 
Apple in later releases of Mac OS X operating systems, AFAIR.)


Quoting wittau at lnxnt.org (wittau at lnxnt.org):

 >> the Linux partition was first on the
 >> disk, that's what the d-i manual recommends

Which manual do you actually refer to? Do you refer to the Debian manual 
for PowerPC installations?


I think that the sequence of partitions used for operating systems 
should not matter too much, and personally I set up my Linux partitions 
in the final section of my hard disk drive ("at the end" of the disk 
space available). After initializing my HDD with Mac OS 9's "Drive 
Setup" / "Laufwerke konfigurieren" eight partitions were created, and 
they were named "Apple", seven times "Macintosh", and 1 x "Patch 
Partition". I did not touch them with the Debian installer, and their 
sizes only come up to an amount of 25kb to about 300kb, each. It seems 
that Mac OS 9 needs these partitions to mount HFS(+) formatted volumes; 
well, actually I am sure of that. The first partition I use for the data 
of my operating systems is "hda9". Preferably, "Mac OS Extended" (HFS+) 
should be used as a file system for Mac OS 9 (and Mac OS X) operating 
systems.

I added several other partitions ("hda10"..."hda16") for my daily work 
purposes. Yet, I created the final Debian partitions on my HDD with the 
Debian installation tool from the netboot.iso disc, I think, i.e. during 
the process of the installation of Debian GNU/Linux. In my case I 
allowed the Debian installer to create a partition "hda17" of 1.0MB 
(could be even less, I think, but I used 1MB; nevermind) as a sort of 
boot partition on NewWorld PowerPC computers for the yaboot boot loader. 
It is followed by a /root partition for Debian GNU/Linux "hda18" sized 
about 12.5GB. On my HDD "hda19" equals a /home partition of 35GB. 
Finally, I opted to use about 1.9GB of disc space on my Swap partition 
"hda20", and that's it, for I own 1.5GB of physical memory in this 
machine.  

Actually, if you're still trying to fix your problem, I think, however, 
that you probably do not have to reorganize your set of partitions; at 
least if you did not destroy any of those small partitions required by 
Mac OS 9.

If your Debian GNU/Linux testing system is up and running and if you did 
not destroy the partitions Mac OS 9 created during the hard disc 
initialisation process (including the HFS partition you used to install 
Mac OS 9 on, of course), please just restart your Macintosh with your 
Mac OS 9 installation CD. If you then run "Drive Setup", respectively 
"Laufwerke konfigurieren" (German system version of Mac OS 9), this 
program will report an IDE disc which was not initialized. Of course, 
you _must_not_ use this tool to initialize your HDD again, for we 
actually KNOW that it has already been initialized by Mac OS 9, whilst 
Debian just added a couple of additional partitions. (If you wanted to 
reinitialize you would have to start over again to install Debian from 
the start.)

So just use this tool "Drive Setup" / "Laufwerke konfigurieren" to 
update the driver ("Treiber aktualisieren") of your hard disk drive. You 
should find this function in a pull-down menu (and you might have to 
"select" this device _once_ with your mouse button before, until its 
background is shaded with a sort of purple color). If Mac OS 9 can 
successfully update your HDD's driver the HFS(+) partition(s) of the Mac 
OS 9 OS you had created before might appear on your screen. Yet, you 
might also have to reboot your Macintosh one more time from the Mac OS 9 
installation CD to (hopefully) see it/them mounted.

Updating the HDD driver using "Drive Setup" does, AFAIK, not have any 
effect on partitions primarily used by Debian GNU/Linux, but do not 
blame me should you encounter any data loss: Please update your HDD 
drivers only on systems you backed up before; the same applies to 
creating additional partitions or changing the partition table.

Of course, your ext2/ext3 or whatever Linux style partitions you use 
will be invisible if you use a standardized Mac OS 9 OS environment; 
Debian GNU/Linux can, however, access partitions with HFS(+) file systems.

Well, I hope that this works and you will see your Mac OS installation 
again. In such a dualboot environment which you intend to set up you can 
switch between Mac OS 9 and Debian GNU/Linux by pressing (and holding 
down) the "alt" key right after you switch on your Mac (or reboot). Then 
you should have the option to use your mouse (or even keyboard) to 
select which OS you want to use.

For a proper "boot loading experience" with the yaboot boot loader, 
please edit the file "/etc/yaboot.conf" according to your needs by 
editing the respective entries for partitions for "Mac OS 9" and 
"/root", then run the script "/sbin/ybin", and restart. Please note: Any 
time you _use_ the Mac OS 9 Control Panel "Startup Disc" ("Startvolume") 
this will reset your yaboot settings and you will need to run /sbin/ybin 
again, and restart. (Once I even decided to archive this Control Panel 
with DropStuff to ensure that I do not accidentally activate it...)

Kind regards,

Sebastian Schroeer