[CentOS] Finally.... CentOS on iMac core 2

[Leon Fauster]

Am 25.11.2013 um 16:22 schrieb Wes James <comptekki at gmail.com>:
> On Sun, Nov 24, 2013 at 5:59 PM, Philip Manuel <phil at zomojo.com> wrote:
>> 
>> From: "Wes James" <comptekki at gmail.com>
>>> I've been trying several combinations of OSX, CentOS to try and get CentOS
>>> installed on an old iMac. I finally first installed OS X, then installed
>>> CentOS in the open space after OS X. With refit installed and selecting
>>> CentOS, it starts booting but get a screen that a boot device can't e
>>> found. So I then install Xubuntu with the option to replace OS X.  After
>>> Xbuntu is installed and then do a reboot the grub screen comes up and I can
>>> now select CentOS and it will boot.
>>> 
>>> Can someone explain why this is?  I can't just install CentOS on the whole
>>> disk, as I get the blinking mac disk with question mark.
>>> 
>> 
>> this is due I believe due to the partitioning scheme of the iMac, using
>> GPT, and as grub does not support GPT partitions. you have to use grub2.
>> Hence, why xubuntu works.
>> 
>> 
> Oh.  OK.  I didn't realize CentOS wasn't using grub2.  Are there any plans
> for CentOS to move to grub2?


there exist a so called "Hybrid GPT/MBR partition table support" in "OSX -> cli tool diskutil"
that leads to the so called "BIOS compatibility" for booting. 

rEFIt includes "Partition Inspector (native osx app)" that shows your GPT -> MBR sync status.

refit can do that "sync" also (in there prompt).

I could boot CentOS5 on a Intel Macbook two years ago (with grub1). 

Alternative - compile Grub2 under OSX, install it under OSX, configure it to boot both (osx/linux), boot it.

Suggestion - use Grub2/EFI not because of the partition format but for better hw initialisation. 
The BIOS compatibility mode (grub1/BIOS) is not doing his job correctly (e.g. ATI GFX Card support etc.).

--
LF