Michel Catudal a écrit :
Le 03/02/2012 19:05, Pierre Jarillon a écrit :
I have installed Mageia on a disk after Ubuntu.
After the install, I reboot and Ubuntu was ignored in Grub.
The owner of the PC was not happy and tought that Mageia is bad.
I have not found how to restore an access to Ubuntu and after an
hour, I have
reinstalled Ubuntu which install its grub2 allowing to boot on both
systems.
In Caudron, grub2 is not still used. Is time to switch to Grub2 ?
I have installed both ubuntu and mageia with no problem with regard to
booting ubuntu.
You must have left ubuntu put the bootloader on the MBR. If you are
going to install several Linux distribution you should install the OS
on partitions and not on the MBR.
On my PC I use xosl as a bootloader and always install grub on the
boot partition. A few years back I got burned when I forgot to change
the default.
One thing that pisses me off on all the Linux distribution, including
Mageia is that the fact that the bootloader is on the MBR is sorta
hidden and it is not obvious how to switch it to the partition. It
should be on the top with boxes with the choice of where we want it
and a message that is not cryptic and makes it obvious what that does.
That way I don't see where we could accidentaly screw up our system.
There is no problem if you have only one operating system to have grub
on the MBR but brain dead to put it there when you have several OS.
Specially when you have diffferent incompatible versions of grub.
The way I recovered the messed up boot was to boot on my xosl boot
diskette and restore its boot.
Here is the layout of one of my hard disks.
Périphérique Amorce Début Fin Blocs Id Système
/dev/sda1 1 1 8001 78 Inconnu <-- xosl
/dev/sda2 2 261 2088450 6 FAT16 <-- Free
Dos
/dev/sda3 * 262 276 120487+ 83 Linux
/dev/sda4 277 243201 1951295062+ 5 Etendue
/dev/sda5 277 750 3807373+ 82 Linux swap /
Solaris
/dev/sda6 751 765 120456 83 Linux
/dev/sda7 766 780 120456 83 Linux
/dev/sda8 781 795 120456 83 Linux
/dev/sda9 796 60000 475564131 83 Linux
/dev/sda10 60001 120000 481949968+ 83 Linux
/dev/sda11 120001 160000 321299968+ 83 Linux
/dev/sda12 160001 200000 321299968+ 83 Linux
/dev/sda13 200001 243201 347012001 83 Linux
Michel
So the key point seems to be a separate boot partition, which links to
the root partitions of the different systems, which each have their
system-specific boot loaders.
That could probably be done with grub without too much problem, if it
can't be installed like that already.
(The initial boot step simply chain-loading to whatever system, as it
already does with ms-based systems.)
Sounds like a lot more stable approach. And it shouldn't take any
longer to boot to Linux.
Or maybe we should package xosl ?
--
André
