On Thu, Jul 2, 2015 at 2:43 AM, ken <gebser@xxxxxxxxxxxx> wrote:
> On 07/01/2015 05:10 PM, Jonathan Billings wrote:
>>
>>
>>> On Jul 1, 2015, at 12:20, Chris Murphy <lists@xxxxxxxxxxxxxxxxx> wrote:
>>>
>>> My understanding is CentOS doesn't really support dual-boot anyway,
>>> whereas Fedora does.
>>
>>
>> Nope. CentOS 5, 6 and 7 all support dual-boot.
Considering CentOS 7, at least, doesn't include ntfsprogs, the
installation of CentOS can't support shrink or discovery of Windows in
order to create a GRUB menu entry for it. That tools exist the user
can make this work after installation is not at all what I'd consider
"supported".
> Since Linux first came out in '92, every distro I've used-- SLS, Slackware,
> Redhat, Suse, CentOS, and probably one or two others-- *all* have allowed
> dual-boot. The feature is built into grub, and lilo before that. Anyone
> who put together a distro which didn't support dual-boot would have to take
> the feature out-- rewrite the code (and why do that just to take out a
> perfectly functioning feature?)--, else use some other boot loader... e.g.,
> the Raspberry Pi distros don't support dual-boot AFAIK.
Dual boot support has a large number of dependencies, it's not just
dependent on GRUB doing the right thing. When ntfsprogs isn't included
on installation media, for example, Windows dual boot isn't going to
happen at install time, you have to do it manually after installing
ntfsprogs.
Further, Anaconda (the installer used by RHEL, CentOS, Fedora) does
not support enabling all LVs at installation time. Therefore GRUB
won't find other Linux installations. So a default CentOS installation
followed by a default Fedora installation, or vice versa; or
CentOS/Fedora n system which then has n+1 installed, renders the n
version unbootable. The user has to fix this post install. I'd hardly
call this form of dual boot support, any kind of support whatsoever.
https://bugzilla.redhat.com/show_bug.cgi?id=825236
Next, the RHEL/CentOS/Fedora GRUB lacks the rather old patches that
SUSE submitted, to bring UEFI Secure Boot to GRUB's chainloader.mod.
Therefore it isn't possible to have Secure Boot enabled, and chainload
Windows 8 (it fails). So that's broken too.
https://bugzilla.redhat.com/show_bug.cgi?id=1170245#c23
Finally, GRUB's grub-mkconfig command doesn't create EFI chainloading
entries for OS X. Instead it wrongly assumes Linux is booted in
CSM-BIOS mode, and has OS X boot entries designed to do an EFI boot
from a BIOS build of GRUB and the result is a kernel panic. For this
to work correctly it needs to chainload Apple's OS X bootloader, which
is the only reliable way to do this now that they've moved to using
their version of a logical volume manager by default, and nothing in
the free software world knows how to read that format yet.
https://bugzilla.redhat.com/show_bug.cgi?id=893179#c16
So pretty much in every possible way this is broken. I don't see how
anyone says dual boot is supported on CentOS. It's barely supported on
Fedora where right now only Windows on BIOS or 'UEFI without Secure
Boot' are supported configurations. It's not even supported to install
Fedora after CentOS, there's no release criteria saying that it must
work, therefore there's no blocking releases on that bug, therefore
it's considered not supported.
--
Chris Murphy
_______________________________________________
CentOS mailing list
CentOS@xxxxxxxxxx
http://lists.centos.org/mailman/listinfo/centos
