[Novalug] boot chains on FC6 ( or in general )

[Kyle Powell]

Didn't see a reply to this so I'll give it a shot.

--- Walt Smith <waltechmail at yahoo.com> wrote:

> 
> Here's the box:
> 
> hde3 is active boot ( it has a * in fdisk, and a /boot )
> hde5  is the actual grub menu used, and had s full RH9 
>         including /boot at one time.
> hde9  has a recently used FC3.  It has a /boot, /, /everything 
> hde10 has a newly installed FC6.  During anaconda install,
>         I specified the hde10 extended/logical partition to
>         be the boot.....  ( and it wouldn't boot, obviously) 
>          until I modified hde5 which has menu's....  hde10 has a /boot
> 
> To be more clear, /boot as well as /, and everything else
> are on each of hde5, hde9 and hde10.  There is a  separate 
> /boot in hde3.
> 
> To make it boot, I edited grub.conf in hde5.
> 
> OK,
> here's the questions:
> Looking backwards----
> How do I tell whose boot is on the MBR?  MS ? grub ? lilo ?

Yum used to have a checkbootloader.py plugin but it went away before yum-2.0
was released. There's also a checkbootloader.py in up2date but Red Hat hasn't
released up2date for Fedora since FC4. You can still find it on rpmfind.net,
and if you install up2date and run checkbootloader.py you'll see something
like:

[root at foo ~]# /usr/share/rhn/up2date_client/checkbootloader.py
Found GRUB.

It only knows LILO and GRUB however. Short of a utility, you can always scan
the MBR yourself. The MBR is the first 512 bytes of the disk, and the
bootloader takes up the first 446 bytes of that (the rest being used for the
four primary partitions and the magic number).

[root at foo ~]# dd if=/dev/hde of=/tmp/mbr.bin bs=512 count=1
[root at foo ~]# strings /tmp/mbr.bin
<snip>
GRUB 
<snip>

I would guess LILO will show LILO some place. No idea about M$.

> How do I tell if I put a boot in the hde3 partition area?

Same thing should work.

[root at foo ~]# dd if=/dev/hde3 of=/tmp/hde3.bin bs=512 count=1
[root at foo ~]# strings /tmp/hde3.bin 
[root at foo ~]# od -x /tmp/hde3.bin 
0000000 0000 0000 0000 0000 0000 0000 0000 0000
*
0001000

> How do I tell where hde5 is actually chained "from"/"to" ?

Sorry, don't understand this question.

> Is it possible I have a boot on the --partition-- of hde5 ? or 9 ?
> how to tell ?  Any tools ??

Yes, it's possible, though unusual. This is the same as the second question
above.

> I -may- want to modify with the MBR or the hde5 to
> boot hde10 --- ?? thru the extended partition boot or grub ?

You really should reconsider your partition layout. Instead of one partition
for each distro, including /boot and all the other supporting directories, you
should create a small partition (say 128MB) to be the /boot for all of them.
Likewise a large /home partition to be shared across all the distros you'll
have installed. Finally create ~4GB partitions for each distro's root fs. This
will simplify things for you. One boot partition, one grub.conf to modify, one
location for all the kernels of your various distros.

-Kyle


 
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