[CentOS] grub-install

[Chris Murphy]

On Fri, Aug 14, 2015 at 7:18 PM, Sachin Gupta <sachin3072004 at gmail.com> wrote:
> Hello Everyone,
>
> I am a newbie. When I try to install GRUB2 on centos 5.2 system, I get
> following error.

CentOS 5 and 6 don't support GRUB 2, only GRUB legacy is supported.
There's a decent chance you could grab a Fedora RPM and it will
install OK but I don't know what version to recommend because CentOS 5
is so much older than even the oldest Fedora that first had GRUB 2.

It's a bit tedious to build GRUB 2 yourself from upstream, but that's
also an option. I only recommend that for computers with BIOS
firmware. There are some significant differences with the UEFI build
of GRUB 2 between upstream and RH/Fedora that might make you want to
drink heavily.

Not that upstream, the commands are grub-install and grub-mkconfig,
whereas for RH/Fedora it's grub2-install and grub2-mkconfig to avoid
confusion with the legacy versions that RH still supports.


>
> centos5: grub-install  /dev/sda
> //sbin/grub-setup: warn: This GPT partition label has no BIOS Boot
> Partition; embedding won't be possible!.
> //sbin/grub-setup: warn: Embedding is not possible.  GRUB can only be
> installed in this setup by using blocklists.  However, blocklists are
> UNRELIABLE and their use is discouraged..
> //sbin/grub-setup: error: will not proceed with blocklists.
>
> Can you please help me figure out the problem ?

Well I can't tell if this grub-install is actually GRUB 2 upstream,
which I suspect it might be because I'm not aware that legacy supports
GPT (?) But since GRUB legacy is from the pleistocene I may have just
forgotten. Anyway, the simplest solution is carve out 1MiB of free
space somehow, and make a 1MiB partition. I suggest using GPT fdisk,
a.k.a. gdisk. Set the partition type to EF02, which will set the
partition type GUID to that of BIOS Boot. And now GRUB should install
- it will automatically find that partition.

If you use parted, the flag to use is biosboot, which does the same
thing as EF02 in gdisk.



-- 
Chris Murphy