Anaconda 17.24-1 reverts to msdos disklabels for new installs

[Brian C. Lane]

Back in Fedora 16 we tried to advance the state of the art. We switched
to using GPT disklabels by default, and in many cases this worked just
fine. But it has become increasingly obvious that the hardware isn't
ready for us. We continue to get reports of boot problems related to
BIOS that attempt to examine the disk before booting and GPT confuses
them -- even when we set the PMBR's boot flag.

So, for Fedora 17 we are going backwards and will wait for the world to
catch up. What's changed:

 * msdos disklabels will be the default for disks under 2TB
 * GPT can be forced by passing gpt on the kernel cmdline
 * nogpt cmdline argument has been removed

This only effects BIOS installs. EFI will continue to use GPT, as will
disks larger than 2T

-- 
Brian C. Lane | Anaconda Team | IRC: bcl #anaconda | Port Orchard, WA (PST8PDT)

[Adam Williamson]

On Tue, 2012-05-01 at 16:08 -0700, Brian C. Lane wrote:
>  Back in Fedora 16 we tried to advance the state of the art. We
> switched
>  to using GPT disklabels by default, and in many cases this worked just
>  fine. But it has become increasingly obvious that the hardware isn't
>  ready for us. We continue to get reports of boot problems related to
>  BIOS that attempt to examine the disk before booting and GPT confuses
>  them -- even when we set the PMBR's boot flag.
>  
>  So, for Fedora 17 we are going backwards and will wait for the world to
>  catch up. What's changed:
>  
>   * msdos disklabels will be the default for disks under 2TB
>   * GPT can be forced by passing gpt on the kernel cmdline
>   * nogpt cmdline argument has been removed
>  
>  This only effects BIOS installs. EFI will continue to use GPT, as will
>  disks larger than 2T 
Honestly, I think the practical lesson of this experience is that there
is a natural 'switchover point' for GPT by default, and that's EFI. I
don't think it's ever going to be the case that we can rely strongly
enough on BIOS installs to boot successfully from GPT disks (except in
the 2TB case obviously). I think we should just stick with MS-DOS disk
labels for native BIOS installs until we stop doing 'em. It's a pain,
but there it is...
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora
http://www.happyassassin.net