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Re: changing default os in grub



On (02/12/04 09:38), john gennard wrote:
> I've been using grub for a little while now, and
> its setup as been 'automatic'.
> 
> I run Sarge and also have Sid installed.
> 
> Frequently, I install debian based distros just to
> have a look at them.
> 
> Now, I have ubuntu as the default selection and Sarge
> is lower down.
> 
> I've just installed a 2.6.8 kernel in Sarge and was
> hoping the adjustment to grub would return Sarge to
> the default position - it didn't.
> 
> I can boot into ubuntu and add the new kernel, but
> this would not put Sarge where I want it to be for
> booting purposes.
> 
> The man and info pages do not appear to help (perhaps
> because I don't fully understand them). I don't want to
> risk making everything unbootable by experimenting, so
> can anyone please explain how I can safely put Sarge
> back as default?
Hi John

You need to edit /boot/grub/menu.lst with a text editor.  I have a
rather complex grub set-up (which was an interesting learning
experience) on a spare windows machine in our office which has two
drives /dev/hda and /dev/hdb; hda has windows 98 and hdb has a vfat
partition for the windows system and 4 Debian based systems on different
partitions but share common swap space.

Here's an extract from my menu.lst:

# This entry is for the windows OS and appears first as the default
# system on /dev/hda1
title           Windows 98SE
root            (hd0,0)  
savedefault
makeactive
chainloader     +1


# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST
# The automagic kernels list includes all the d-i sarge kernels which
# update automatically.  Note that the groot (grub root) is on the
# second disk
### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default optons below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specifiv kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
# kopt=root=/dev/hdb2 ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=(hd1,1)

## should update-grub create alternative automagic boot options
## e.g. alternative=true
##      alternative=false
# alternative=true

## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
##      lockalternative=false
# lockalternative=false

## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
##      altoptions=(recovery mode) single
# altoptions=(recovery mode) single

## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
##      howmany=7
# howmany=all

## ## End Default Options ##

title           Debian GNU/Linux, kernel 2.6.8-1-686
root            (hd1,1)
kernel          /boot/vmlinuz-2.6.8-1-686 root=/dev/hdb2 ro
initrd          /boot/initrd.img-2.6.8-1-686
savedefault
boot

title           Debian GNU/Linux, kernel 2.6.8-1-686 (recovery mode)
root            (hd1,1)
kernel          /boot/vmlinuz-2.6.8-1-686 root=/dev/hdb2 ro single
initrd          /boot/initrd.img-2.6.8-1-686
savedefault
boot

title           Debian GNU/Linux, kernel 2.4.27-1-386
root            (hd1,1)
kernel          /boot/vmlinuz-2.4.27-1-386 root=/dev/hdb2 ro
initrd          /boot/initrd.img-2.4.27-1-386
savedefault
boot

title           Debian GNU/Linux, kernel 2.4.27-1-386 (recovery mode)
root            (hd1,1)
kernel          /boot/vmlinuz-2.4.27-1-386 root=/dev/hdb2 ro single
initrd          /boot/initrd.img-2.4.27-1-386
savedefault
boot

### END DEBIAN AUTOMAGIC KERNELS LIST

# This is a divider, added to separate the menu items below from the
# Debian sarge ones. Here I've manually inserted the details of Ubuntu,
# and MEPIS.  Note that Xandros uses LILO by default and offers
# no easy way to install grub. I can only boot into Xandros from a boot
# floppy.  My advice is don't mix Xandros with grub ;)
title           Other operating systems:
root


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hdb9.
title           Ubuntu, kernel 2.6.8.1-3-386 (on /dev/hdb9)
root            (hd1,8)
kernel          /boot/vmlinuz-2.6.8.1-3-386 root=/dev/hdb9 ro quiet
splash
initrd          /boot/initrd.img-2.6.8.1-3-386
savedefault
boot


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hdb9.
title           Ubuntu, kernel 2.6.8.1-3-386 (recovery mode) (on
/dev/hdb9)
root            (hd1,8)
kernel          /boot/vmlinuz-2.6.8.1-3-386 root=/dev/hdb9 ro single
initrd          /boot/initrd.img-2.6.8.1-3-386
savedefault
boot


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hdb11.
title           MEPIS, kernel 2.4.26 (on /dev/hdb11)
root            (hd1,10)
kernel          /boot/vmlinuz-2.4.26 root=/dev/hdb11 ro
savedefault
boot


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hdb11.
title           MEPIS, kernel 2.4.26 (recovery mode) (on /dev/hdb11)
root            (hd1,10)
kernel          /boot/vmlinuz-2.4.26 root=/dev/hdb11 ro single
savedefault
boot


# This entry automatically added by the Debian installer for an existing
# linux installation on /dev/hdb11.
title           Run MEMTEST to test system memory (on /dev/hdb11)
root            (hd1,10)
kernel          /boot/memtest86.bin root=/dev/hdb11
savedefault
boot

Once you've edited your menu.lst run update-grub but make sure you have
also made a grub floppy to get you out of trouble, if necessary.  Look
at the GRUB in Debian HOWTO:

http://www.linuxorbit.com/modules.php?op=modload&name=Sections&file=index&req=viewarticle&artid=539

HTH

Clive

-- 
www.clivemenzies.co.uk ...
...strategies for business




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