[Mageia-dev] Grub and Grub2

[Michel Catudal]

Le 2012-02-04 04:32, andre999 a écrit :
> 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 ?
>

I have been using xosl for years and it works like a charm. On my computer I needed to install eComStation 2.1(OS/2) and it wants to be on drive A: just like windows. I disconnected the other drives and installed it. After the installation I put my other 2 
2TB hards in and put the OS/2 disk as the 3rd disk.
With xosl it was a breeze, you just tell it to swap drives. On my son's computer I have Win XP as the second drive, using the same method.

The beauty with this is that you never have to worry about windows or OS/2 screwing up your Linux systems during its installation. With the low cost of hard disks it no longer make sense to try to put windows and linux on the same drive. You are still 
stuck with the old approach on a laptop though.
As far as I am concerned I will never use a laptop, the screen and keyboards are too damm small.

One note on an issue I mentionned before with disk swaps by the bios.  The motherboard is a K9A2 form MSI. Just in case someone else had the same issue, you will find that very instructive.

I have Scientific Linux, Ubuntu and Centos installed on the second drive, eComStation 2.1 on the third drive and Fedora 13, Mandriva 2000.1, Gentoo and Fedora 15 on the first drive. I then installed mageia on the second drive. After reboot it would not 
boot on mageia or OS/2 but would boot on any OS on the first drive. It turned out that the drives had been swapped internally before the reboot. I found out recently that the reason had to do with boot sequence in the bios.
Because of a storm the computer had shutdown and somehow the bios info had some odd boot sequence. The solution was to make sure that only the floppy, DVD (4th sata drive) and first disk would be in the list of bootable device.

The boot sequence was DVD, 1st and 3rd hard disk when I had the drive swap issue.
With that issue the grub installation saw the 3rd drive as the second drive and mageia saw the second drive correctly as /dev/sdb
It would not boot until I made a change in menu.lst to swap the drive for grub. I had to do the same on the other Linux
Everytime I would update on Mageia I could no longer boot on Mageia. I didn't have that problem on Scientific Linux.

Lately I am using mostly gentoo, I may actually dump Mageia in the future if it is not possible to have gnome 2 or mate. Gnome 2 still works beautifully on gentoo.
I hate gnome 3 with a passion and I find kde too slow compared to gnome 2.


Michel


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