booting multiple OS

alex aradsky at
Wed Aug 29 16:38:57 UTC 2007

Derek Broughton wrote:
> ruscook wrote:
>> I've a question re: "best practice" for booting multple OS off a single
>> HDD.
> Best practice?  Only install Ubuntu :-)
>> The first problem I have so far is each OS I install overwrites the grub
>> config of the previous one, rather than adding to it.

I have 9 OS installed including Windows XP.( two ubuntu's, one from DVD)

At first, the effective  /boot/grub/menu.lst  was in the last installed 
OS so that system was the
default 3 second delayed boot.   All the previously installed systems 
had an entry in /boot/grub/menu.lst
of the last installed system..

I then  used an editor from the default system to examine  
/boot/ to find the
the entries that did not start with #.

I edited the order of entries so that Windows was the first (default  3 
second delayed autoboot) system.  ( My computer is used by kids (aged 4 
to 7) to play their games from CD in Windows  and I didn't want to let 
them to get into the other systems until they're more computer savvy..

I edited menu.lst so that the last installed system was the second entry 
(after Windows) .
Then I edited to put the other systems in the order that I wanted them 
to appear on the bootup menu.

Finally, I saved back to /boot/grub/menu.lst.

Upon restarting the computer, the revised boot menu showed up and I was 
able to access any of the installed systems.

I accessed each of the systems and edited its menu.lst to that it had 
entries that were identical to those just ,made.  This doesn't have to 
be done.   It's a belt and suspenders thing in the event you want to use 
a different system to do the booting.


Except for modifying  the last  installed system's menu.lst  to have 
Windows  autoboot  in 3 seconds.

I was able to boot any of the previously installed systems

>> Should I use ONE /boot (dev/sda1 in this case) and share it with all OS
>> or should I just leave /boot as part of the / of each OS (i.e. have a
>> separate /boot for each OS)? If I use a separate boot partitions for
>> each OS, how do I do multi-boot?
> I've done it both ways, and both have their advantages (these days I don't
> multiboot at all), but if you have just one /boot partition, at the very
> least Ubuntu is able to leave the other OS's grub stanzas alone.  I
> wouldn't count on all of them to be so careful, but Ubuntu will auto-update
> the parts between the "DEBIAN AUTOMAGIC KERNELS" tags, and not anything
> else, so you keep the other OS's stanzas outside that part.  If they have
> some similar magic, you may be able to have a section for each OS.
>> The second issue, I've made a primary partition for BSD (as it doesn't
>> seem to work with logical partitions), but I'm not sure how to install
>> the BSD boot loader. Should it go at the beginning of the partition I
>> install BSD to and try and make sure I leave the MBR for GRUB?
> Sorry, can't help with BSD.

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