Shared /boot partition?

[Bill Davidsen]

I have to set up a machine to boot both 32 and 64 bit Fedora (or RHEL if I wish) 
and while I know how to do it with separate partitions and copy information from 
one grub.conf to the other so I can choose at boot time, I was wondering if I 
could share a /boot partition between 32 and 64 bit installs.

It would make life a *lot* easier if I could.

[Sam Varshavchik]

Bill Davidsen writes:
> I have to set up a machine to boot both 32 and 64 bit Fedora (or RHEL if I wish) 
> and while I know how to do it with separate partitions and copy information from 
> one grub.conf to the other so I can choose at boot time, I was wondering if I 
> could share a /boot partition between 32 and 64 bit installs.
>
> It would make life a *lot* easier if I could.

Although I see no reason why this can't be done, you're going to confuse yum 
when you use it to install updated kernels. It'll find entries in grub.conf 
that reference kernels for the other system. This will probably confuse the 
code that automatically uninstalls older code.

Setting this issue aside, install the first system without a separate boot 
partition, so /boot lives on its root. Now, install the second system, with 
a separate /boot partition. Temporary mount the first system's root 
partition, and copy over the contents of it's boot to the separate boot 
partition, and update it's grub.conf accordingly.

Boot back into the first system, remove it's /boot, and mount the new /boot 
partition in it's place, and update it's fstab.

[Michael J Gruber]

Bill Davidsen venit, vidit, dixit 14.03.2009 16:29:
> I have to set up a machine to boot both 32 and 64 bit Fedora (or RHEL if I wish) 
> and while I know how to do it with separate partitions and copy information from 
> one grub.conf to the other so I can choose at boot time, I was wondering if I 
> could share a /boot partition between 32 and 64 bit installs.
>
> It would make life a *lot* easier if I could.

For me the easiest approach is:

Have your 32 and 64 bit distros install grub in their respective
partitions, not mbr.

Have another grub in mbr with a small boot partition. Configure it to
chainload the partitions of the distros.

That is, you first boot manager let's you choose the distro, and then
that boots with it's own boot loader. Cutting down the defult boot delay
on them helps quite a bit with this approach ;)

Michael