Bug#623946: grub-pc: M/C unbootable if primary bootable flag not set

[Rustom Mody]

On Mon, Apr 25, 2011 at 12:35 AM, Colin Watson <cjwatson at debian.org> wrote:
> On Sun, Apr 24, 2011 at 11:05:07PM +0530, Rustom Mody wrote:
>> I moved my boot  partition to a logical sector
>> Running dpkg-reconfigure grub-pc said it had gone through without error
>> However the disk remained unbootable until a primary (or extended) partition
>> was flagged as bootable
>>
>> It would be good if grub install were to warn about installing to a logical
>> partition with bootable flag set
>
> I don't think this is any of GRUB's business, honestly.  GRUB itself
> doesn't care whether the partition is marked bootable or not.  If
> anything cares, it will be your BIOS - but only some BIOSes care about
> this.

Exactly so -- in a logical world!
Unfortunately Intel boards/BIOSes sometimes treat as unbootable a disk
in which the bootable flag is on in a logical partition -- not so
logical :D

Also I agree that this is not a debian problem but primarily a grub
issue so maybe I take it up there?

In summary: a recipe for those reaching here through a search engine:
1. grub-install makes an unbootable system if a logical partition is
marked as bootable
(and says the installation is problem-free to boot !)
2. Just turn on the bootable flag on some (probably irrelevant)
primary/extended partition
3. This is so at least for (some) intel boards