update grub + 2 ubtuntu installs with shared /boot

[Gary W. Swearingen]

Philip Lawatsch <philip at lawatsch.at> writes:

> I've no problem understanding / using grub, I've only got a problem
> understanding all the automatisms which are in ubuntu and deal with grub.

Yeah.  I hear a new Slackware version has come out, or soon.

> Well, if I want the comfort of automagically booting the correct kernel
> even after an upgrade then I have to have some hack in place to allow
> update-grub to update menu.lst without breaking the other install.
>
> For this to work with 2 installs every install needs to have a seperate
> menu.lst

And thus two /boot dirs, which I thought you said you didn't want.

> And for this to work I would need at least 2 grub installs, where one
> grub starts the other grub (and have only one grub installed in the mbr).
>
> In my case I'm going to have one grub installed in the mbr which will
> start a bsd install, a windows install and then a different grub for
> each of the two ubuntu installs.

Sounds good, if the ubuntu install offers installing grub bootloader
to a partition.  You didn't say where the MBR's menu.lst is, but let's
say in the BSD "/boot/grub".  You could then edit that to boot the two
ubuntus directly.  And I'd probably not even bother installing the
extra bootloaders to the partitions.  But if you do, you don't even
need grub in the MBR; you can use the much simpler BSD bootloader
which simply offers you a choice of partitions (or second disk) to
boot from.