Strange behaviour in Disk Druid

Robert Moskowitz rgm at
Thu Dec 8 21:43:34 UTC 2011

On 12/08/2011 04:14 PM, Adam Williamson wrote:
> 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.

Well if the manufacturer wants a default of EFI, who am I to argue?  :)

Um, I grew up with BIOS (well really before BIOS, I go back to teletypes 
at 55 baud and GE Mark IVs and real Dartmouth BASIC), and EFI is 'new' 
to me.  Can you point me to a basic intro to it?

>> 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.

I will note this for any other F16 install that goes with EFI!  I 
believe I can deal with the 11Gb 'waste' as I am moving from a 60Gb to a 
320Gb drive and really not much into movies or such.

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