I run Debian, and I have installed Sarge and Unstable plus
W2000. Normally, I have up to another four or five distros
that I'm 'having a look at' on a temporary basis.

Grub will have the various Sarge kernels first, with a specific
one as default. Then come W2000, the various Unstable
kernels and finally the temporary installations.

If I install say Mepis, I configure no bootloader, but edit
Grub in Sarge to allow me to boot Mepis. So far this has
given no problems.

Recently, I installed Ububtu and 'took my eye off the ball'
so that it installed Ubuntu on the Mbr and installed it as
the default. This is annoying, having to drop down to Sarge
each time I boot up, so I want to return Sarge to the default
position.

It seems a simple thing to do. However, I'm confused as to
the best way to proceed (also wary of finishing with an
unbootable situation - I have a Grub bootable floppy,
but haven't yet tried using it)

I've read the manpage for 'update-grub', and can't comprehend
exactly what it does. It doesn't seem to do the same as
running 'lilo' after changes.

Googling hasn't so far given me any clear help on this specific
problem. Where I'm all at sea, is that grub is on the Mbr (something
I know virtually nothing about), so how do I safely edit it, or
replace it with a revised version that meets me wishes.

Can someone help, please?. On the general question of grub
I think I have a good understanding, it just this aspect (and
probably excessive wariness on my part!).

John.

rabelais,

I think what you want to do is edit your /etc/grub.conf file. In there you should see a line 'default=x' where x is a number from 0 to the number of OSes recognised.

You will also see a list of each of the systems, each beginning with a "title blah" tag. This marks the start of each OS definition.

So, as you have probably guessed you just need to change the 'x' to the number matching the distro you want as default. Be careful to get the numbering correct. Remember the first system listed is actually number ZERO.

good luck!

Thank you, but that will be difficult as I do not have
a grub.conf file in /etc. Neither in Sarge nor Ubuntu (I
haven't checked all the distros, but imagine they will
be all the same). What distro are you using?

it's located in /boot/ or /boot/grub I belive...

The location of the file is You can edit it to change the default boot selection. Numbering on the list starts with 0, so "1" would be the second entry.

I have installed
30GB /dev/hda1 - Slackware 10
10GB - FreeBSD 5.3
20GB /dev/hde1 - Debian Sarge
60GB - free space for testing
I always use GAG bootloader. It supports up to 9 OS. In fact, the configuration is not even necessary to save either to floppy of HD. I have just loaded into Slackware after installing CRUX without saving GAG configuration.

I run 4 distros using one installation of grub. Someone on this forum said they ran 5 using grub. Another good thing would be to put grub on a floppy as well, just in case things go wrong.

The guy who runs distrowatch.com has 25 different operating syatems on his disks. He wrote a multiple boot howto here: http://distrowatch.com/weekly.php?issue=20040614#2

My point was to express that other options exist. And there is always a way.

I am using FC3. I happen to have both the /etc/grub.conf and /boot/grub/menu.lst files and I can modify either one with the changes being mirrored. I suspect there is a link there or something.

You might also find that your distro comes with a bootloader configuration program. I know FC3 does under one of the system tools menus.

If you have anymore questions, you know where to find us!

adriaanbw,

Thanks, I did understand most of the /boot/grub/menu.lst
file, although the notes on setting the default entry were a
little confusing to me. I've now experimented and find the
'numbers 0 upwards' means the distributions and other
programmes (eg. recovery and memory testing) in the
order in which they appear in the config file.

However, the area I fail to understand still remains.
Because I allowed Ubuntu to install Grub, the config file
which allows me to make changes is in /boot/grub/menu.lst
in Ubuntu. At some time I shall want to get rid of Ubuntu
(I normally get rid of distros I'm just 'having a look at' by
formatting the partitions in which they were installed), and
it seems to me that something on the Mbr will, on booting,
say something like "have a look in /dev/hdax (aka Ubuntu)
/boot/grub/ and offer for booting the contents of /boot/grub/menu.lst". There'll be nothing there as the
partition is empty. Now what happens?

I have /boot/grub/menu.lst in Debian Sarge which has the
booting options exactly as I want them, but there can't be
any 'link' to the drive Mbr. That is what I have to achieve
before I can get rid of any temporary distros. I have not been
in this position before as I always upgraded Debian (from
Potato to Woody to Sarge - Sid which I also have was a
copy of Sarge which I upgraded to Unstable).

John.