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

[Sebastian Schroeer]

Hi Mathias,

thanks for the report you've written after you have had so many troubles 
with your PowerMac G4.

Of course, it is crucial to either use hard disk drives supported by 
your early G4 Power Mac's internal PATA controller (i.e. devices 
featuring a capacity of up to 128GB in early Power Mac G4 machines, I 
think) or to connect HDDs with a higher capacity with it and restrict 
their disk space usable to a maximum of 128GB. It is interesting that 
connecting HDDs with a higher capacity and restricting their disk space 
usable to a maximum of 128GB seems only to work if operating systems 
like Mac OS 9 and Mac OS X are used (and no longer as soon as Debian 
GNU/Linux gets involved).

Using an operating system like Debian GNU/Linux does, of course, not 
automatically mean that this is a way of easily exceeding the limits of 
your HDD controller.

I also do not expect that disk errors similar to the ones you reported 
will occur if Power Mac users use special PCI addon cards to operate 
bigger PATA/IDE or SATA disk drives - at least if those PCI addon cards 
are suitable to be used in Power PC Macs (see the product specifications 
and system requirements of e.g. ACARD addon cards). (Personally, 
however, I've never tried to use a HDD controller extension card in a 
Power Mac with Debian GNU/Linux; I only know that such an extension card 
works perfectly in my OldWorld Power Mac 7300 running Mac OS 7 and 9. 
But currently I'm not running Linux on this particular machine, only on 
my Power Mac 7500.)


 > -) trying to fix the problem when using bigger disks at the original 
built
 > in controllers (but beware, as recent Terrabyte disks are no problems
 > throught PCI cards, and seem to be used often at G4s)

I'm not sure if I understand correctly what you're stating here. To be 
honest, I think it is rather unlikely that a software solution within 
the Debian GNU/Linux installation tool allowing you to reliably use 
bigger disks (> 128 GB) connected with the original built-in PATA/IDE 
controller of early Power Mac G4 computers will ever be released. Yet, 
it seems that there was a way of doing this, using a special workaround 
tool, but this product is commercial software and therefore AFAIK it is 
not subject to GPL licence conditions:

http://www.apfeltalk.de/forum/neue-festplatte-powermac-t84599-2.html#post2678601

http://www.macupdate.com/app/mac/14544/speedtools-ata-hi-cap-support-driver

Currently I am not aware of any reports stating that this tool works 
together with Debian GNU/Linux installations or of reports that it does 
not work, thus it seems that using this tool _might_ allow you to use 
bigger HDDs with your system while you would not have to buy new 
hardware products. Probably you would have to check this yourself...


The use of hardware extension cards for the PCI slots might be an option 
allowing you to use larger hard disks - if those extension cards are 
suitable for Power Mac G4 computers, of course. Personally I'd prefer 
this option, for using hardware extension cards might even speed up your 
system's data transfer rates.


The subject of this bug report might imply that there was an 
installation problem if you try to use Debian GNU/Linux together with 
Mac OS 9 on one ("big") hard disk, on various partitions of an early 
Power Mac G4 system. In fact, I think that if you try to use any other 
operating system (like Mac OS X or even MorphOS) in a similar way 
together with Debian GNU/Linux, i.e. by creating several disk partitions 
on a huge hard disk drive > 128GB connected with one of the internal 
PATA/IDE ports of early Power Mac G4 computers, it is likely that 
similar problems will occur, either during the installation process, or 
- even worse - during the operation of those operating systems at a 
later point in time, and, of course, this would mean that there is a 
high danger of data loss.


 > -) downgrade the bug if needed, as it only affects early G4 Macs with
 > upgraded HDs bigger than 128 GB which do not use the availaible space 
over
 > 128 GB.

I remember that a couple of years ago reports were printed in various 
Macintosh computer magazines recommending users of early G4 Macs to use 
HDDs bigger than 128 GB only in such a way with their machines. I think 
we could really say that it is a matter of "tough luck", for it seems 
that running Debian GNU/Linux using such a hardware environment was not 
tested back in those days, but, on the other hand, one could not really 
expect this of journalists. There are still a few references on internet 
forums available about which G4 Macs were affected by this 128 GB 
problem, whilst others weren't:

http://discussions.apple.com/thread.jspa?threadID=1823678

http://forums.xlr8yourmac.com/action.lasso?-database=faq.fp3&layout=FaqList&-response=answer.faq.lasso&-recordID=34188&-search


Kind regards,


Sebastian Schroeer