On Thu, 2011-08-25 at 17:11 -0700, Adam Williamson wrote:
On Thu, 2011-08-25 at 16:17 -0600, Andrew McNabb wrote:
> While installing Fedora 16 Alpha, I ran into some problems that turned
> out to be caused by the installer formatting with a GPT rather than an
> MBR partition table.
> I would like to understand the change and its implications, and I have
> unsuccessfully tried to track down more information. I haven't been
> able to find anything in the Fedora 16 Alpha Release Notes or the Grub2
> feature page. The only definitive reference I've been able to find is
> the comment "x86 uses GPT disklabels by default on all machines, even
> non-EFI" on the Anaconda/Changes wiki page.
> There seem to be some complications associated with the change. For
> example, Windows can only support GPT on UEFI machines, so dual-booting
> appears to be unsupported (I could not find an option for MBR partition
> tables in the installer).
> Where should I look for more information? Thanks.
To boot to a GPT disk from BIOS (rather than EFI) you need a BIOS boot
partition. If you use one of the automatic partitioning methods, rather
than manual partitioning, F16's installer will create one for you. If
you choose manual partitioning on a BIOS system and don't create a BIOS
boot partition, anaconda will pop up a (somewhat cryptic) warning.
This is changing from a suggestion to a requirement, based on the fact
that grub2 will not even try to install itself without the bios boot
If you're installing alongside an existing copy of Windows I believe
anaconda ought to leave the disk label alone (MSDOS) anyway, though I'm
not sure we've tested that. It should only write a new one if you're
blowing away any existing partitions on the disk, I think. (IMBW on this
This is correct.
It's also true that if you create an msdos/mbr partition table on your
disk prior to installation and then choose any option except for "Use
All Space" (or "clearpart --all" in kickstart) anaconda will not destroy
your existing partition table.
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