[Bug 872826] f18 anaconda - no option to install bootloader to a partition

[Chris Murphy]

On Dec 2, 2012, at 4:12 PM, Kevin Fenzi <kevin at scrye.com> wrote:

> On Sun, 02 Dec 2012 17:32:20 -0500
> Felix Miata <mrmazda at earthlink.net> wrote:
> 
>> On 2012-12-02 19:21 (GMT) bugzilla at redhat.com composed:
>> 
>>> https://bugzilla.redhat.com/show_bug.cgi?id=872826
>> 
>>> --- Comment #19 from Chris Murphy ---
>>> Anaconda should not offer options that are expressly stated as not
>>> recommended by upstream. The problem is ext4's boot sector is only
>>> 512 bytes, which is not enough space. The use of --force fragments
>>> GRUB, and installs the pieces into free space without informing the
>>> file system. At any future time the file system can step on any one
>>> of those block lists and render the system unbootable
> 
> This sounds like a different bug than the one thats in the report
> above. I'd advise the commenter to open a new one on mkfs or anaconda
> to change the boot sector padding. 

I'm not seeing such an option in mke2fs. If it is possible to change the padding/offset, then it would be possible for a continuous installation of GRUB2's boot.img and core.img, without using block lists.

I did get slightly incorrect, ext4 has two boot sectors, for a total of 1024 bytes of code which is still too small for GRUB to fit without block lists. I'm curious how other bootloaders get away with less.

Chris Murphy