Serious GRUB booting problem after install Ubuntu 9.10beta for testing it.

[Goh Lip]

Lucio M Nicolosi wrote:
> On Sun, Oct 11, 2009 at 10:49 PM, Luis Maceira <luis_a_maceira at yahoo.com> wrote:
>> I installed 9.10beta for testing it on an external USB HDD partition (/dev/sdb7),and I have 9.04 on /dev/sdb5(where the default GRUB stage2 is),I also have 9.04 on the internal SSD drive ( partition /dev/sda3 ).Now I am not able to boot Ubuntu 9.04 on my internal SSD drive.
>>
>> When I disconnect my external USB HDD the booting process gives me:
>>
>> GRUB loading...
>>
>> error: no such disk
>>
>> grub rescue>_
>>
>> When the external USB HDD is connected and I call the GRUB menu and it appears,the system(9.04) on the internal SSD appears normally on the GRUB menu (I think everything is OK) choose booting the SSD but then the warning:
>>
>> Error 17 : cannot mount selected partition
>>
>> Press any key to continue...    (and return back to GRUB menu)
>>
>> From my working systems 9.04 and 9.10 on the USB HDD I mount the filesystem on the internal SSD and everything appears OK even the /boot/grub directory,so in my opinion the installer of Ubuntu 9.10beta messed up with GRUB stage 1 on the MBR of the internal SSD and the way to the right partition /dev/sda3 is lost.
>>
>> Any way to revert this ? without installing Ubuntu from scratch on the internal SSD.
> 
> Luis,
> 
> Perhaps you could begin by reading the thread:
> 
> "Grub 2 in Jaunty/Karmic can break double boot configuration"
> 
> and:
> 
> http://grub.enbug.org/Manual
> 
> If you are still runing Grub Legacy, booting with a Live CD (9.04 or
> older) may help you edit menu.lst  and set the boot point correctly.
> 
> After that, install Grub2 on 9.04 (suppose it is your current version)
> and I guess your problems are (almost) gone.
> 
> Boa sorte.
> 
> L.
> 
> --
> L M Nicolosi, Eng.
> Lat.:  23°34'4.79"S - Long.: 46°39'59.53"W
> Linux Regist. User #481505 - http://counter.li.org/
> 5E42 E02F E21D 171B EA82  1876 621D 17EB AEBA 4B50
> 


To add to Lucio's, @livecd, after root, setup, manually edit menu.lst to 
*chainload* to 9.10.

Another thing to watch out...9.10 beta has many kernel upgrades and if 
you set your 9.10 installation to overide mbr, (very likely), after each 
upgrade, it will again overide mbr rendering your 9.04 unbootable again.
So it's back to 9.04 livecd again. (a blank grub-legacy cd will be handy)

Or you can keep your setup as is, and if you want to boot into 9.04, you 
will need to keep the external HD (9.10) on. If 9.04 has any upgrade, 
make sure you follow up by updating 9.10 grub config as well.

Also note even if you change 9.04 to grub2, any upgrade in 9.10 will set 
9.10 boot to mbr and you will still need the ext HD to boot 9.04.


Note that, even if 9.10  and 9.04 were to be on grub-legacy, and there 
is no grub2 to contend with, the above scenarios will still apply. Grub2 
is not an issue.


Regards,
Goh Lip