multibooting linux

[Tom H]

On Wed, Jun 23, 2010 at 12:13 PM, JD <jd1008 at gmail.com> wrote:
> On 06/23/2010 04:31 AM, Steven I Usdansky was caught red-handed while
> writing::
>> My vote is for one grub to rule them all, each distro's grub goes into
>> / rather than the mbr, and the master grub just chainloads each distro's
>> grub. I had been setting up the master grub to point to /vmlinuz and
>> /initrd in each distro, but that involves updating the appropriate symlinks
>> each time a new kernel is installed. Having come across a few distros
>> that insist on installing a bootloader whether I want it or not,
>> chainloading appears to be the only sane way to deal with them, even if
>> it adds a few seconds to the boot sequence.
>
> You get a yes vote from me :)

I don't understand the concept of a "master grub."

Assume that Debian, Fedora, and Ubuntu are all installed on a box.
Surely, the last one where grub-install is run is the one to which
grub is "attached."

Assume that it is Ubuntu and that Fedora's kernel and grub.conf are
updated, unless Ubuntu's menu.lst/grub.cfg is updated, Fedora's new
kernel will not show up in grub's boot menu.

AFAIK, there are five ways to update Ubuntu's menu.lst/grub.cfg:

1. Mount Ubuntu's /boot and edit menu.lst/grub.cfg.

2. Mount Ubuntu's partitions, chroot into its /, and run update-grub.

3. Reboot into Ubuntu and run update-grub.

4. Set up Ubuntu's menu.lst/grub.cfg to load Debian and Fedora's grub
config with configfile (if possible) or chainload so as not to have to
update Ubuntu's menu.lst/grub.cfg in order to add Debian and Fedora's
new kernels to grub's boot menu automagically.

5. Set up Ubuntu's menu.lst/grub.cfg to point to /vmlinuz and
/initramfs-/initrd symlinks for all three installs and update the
symlinks after a kernel upgrade (as described above).