Strange behaviour in Disk Druid

[Adam Williamson]

On Thu, 2011-12-08 at 16:07 -0500, Robert Moskowitz wrote:
> 
> On 12/08/2011 01:26 PM, Adam Williamson wrote:
> > On Thu, 2011-12-08 at 08:31 -0500, Robert Moskowitz wrote:
> >> This is a FC16 x86_64 install, but perhaps it is also in the current
> >> development and you might want to look into this...
> >>
> >> This is my first FC16 install and I had skipped FC15. (that is my prior
> >> experiences are with FC14)
> >>
> >> I like to override the default LVM setup with my own preferences, so
> >> with past installs I have delete the LVM group that would result in the
> >> LVM partition being returned to the free space list for my to then use
> >> for reallocation.
> >>
> >> The FC16 Disk Druid dropped all that freed up space into the EFI
> >> partition (I don't have that screen in front of me right now for the
> >> details and this EFI partition is new to me, that is was not in FC14
> >> installs) instead of into free space.
> > You only get an EFI system partition if you do an EFI install. EFI is
> > the new standard for PC system firmware, it's intended to replace the
> > BIOS format; all systems that use EFI firmware currently also support
> > BIOS emulation mode (CSM), and Fedora boot images are capable of being
> > booted in both EFI mode and BIOS mode. Whether you wind up booting in
> > EFI mode or BIOS mode is a function of how your system handles the
> > choice for the type of media you happen to use for the install, they all
> > seem to do it a bit differently.
> 
> This is a bit confusing to me, being just a general abuser of Fedora  :)
> 
> I did not select an EFI install.  I just purchased a Lenovo x120e and 
> built the F16 x86_64 DVD from the iso I downloaded.  I also downloaded 
> the updates so I would have a local update repo, but this did not come 
> into play until it was time to select the stuff to actually install.  So 
> the 64 DVD defaulted to EFI for the x120e.  

It's the other way around. The system decides which mode to boot in,
Fedora can't make that decision. All systems seem to handle the choice
of which mode to boot in and how to present that choice to the user (if
at all) differently - as I noted.

It sounds like your system is coded to boot by default in native EFI
mode on media that support it, and only use BIOS emulation on media that
can't do native EFI boot.

If you look around in the boot menu / BIOS configuration you may find an
option to configure this, but as I said, it's different on all systems.
On mine, for instance, the boot menu lists media that support EFI
booting twice, one of the entries boots that medium via native EFI and
the other does it via BIOS emulation. The default is BIOS emulation, on
my system: I have to explicitly pick the EFI entry if I want to do a
native EFI boot.

> The EFI partition was 
> initially ~11.7Gb and grew to all of the available space when I deleted 
> the LVM group.

dlehman explained that in his reply. It's just a bug in F16's logic for
determining the size of the partition, it had no hard upper limit, so
the partition would often wind up being created unreasonably large. It's
perfectly safe to manually change it to 200MB in size.
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora
http://www.happyassassin.net