316479
October 9th, 2012, 07:20 PM
I was trying to install an 12.04.1 LTS system on a computer with
an existing 10.04.4 system.
I was trying to be very careful not to wreck my existing 10.04.4
system so I did
grub-install /dev/sdb
where the separate boot partition for my new 12.04.1 system was on /dev/sdc1 and my existing 10.04.4 system had grub installed on /dev/sda
I was unable to boot using the grub installed on /dev/sdb,
I kept getting error 15 (file not found) when trying to load
stage 1.5 This error 15 did not correspond to any of the
Error 15 reports that I could find on the web.
THE SOLUTION
It appears that legacy grub does not correctly handle the case
of booting from an MBR that is on a different disk from the
/boot partition.
My fix was to do
grub-install /dev/sdc
so grub was booting from the MBR of the disk that contained the /boot partition. After changing the BIOS to boot from /dev/sdc
I was able to successfully boot my 12.04.1 system using
the legacy grub that I'd installed.
an existing 10.04.4 system.
I was trying to be very careful not to wreck my existing 10.04.4
system so I did
grub-install /dev/sdb
where the separate boot partition for my new 12.04.1 system was on /dev/sdc1 and my existing 10.04.4 system had grub installed on /dev/sda
I was unable to boot using the grub installed on /dev/sdb,
I kept getting error 15 (file not found) when trying to load
stage 1.5 This error 15 did not correspond to any of the
Error 15 reports that I could find on the web.
THE SOLUTION
It appears that legacy grub does not correctly handle the case
of booting from an MBR that is on a different disk from the
/boot partition.
My fix was to do
grub-install /dev/sdc
so grub was booting from the MBR of the disk that contained the /boot partition. After changing the BIOS to boot from /dev/sdc
I was able to successfully boot my 12.04.1 system using
the legacy grub that I'd installed.