Setting version to Cauldron as installer bugs can only be fixed there (if it's later established that there's a grub/kernel issue with regard to the kernel upgrade issue described above, it can of course lead to an update for Mageia 5).

Version: 5 => Cauldron

I understand Rémi,
nevertheless, config about PC with Grub Legacy
inxi -F
System:    Host: localhost Kernel: 4.1.8-desktop-1.mga5 x86_64 (64 bit) Desktop: KDE 4.14.5 
           Distro: Mageia 5 thornicroft 
Machine:   Mobo: ASUSTeK model: P5B v: Rev 1.xx Bios: American Megatrends v: 2104 date: 03/09/2009
CPU:       Single core Intel Pentium 4 (-HT-) cache: 2048 KB 
           Clock Speeds: 1: 3000 MHz 2: 3000 MHz
Graphics:  Card: NVIDIA NV44 [Quadro NVS 285]
           Display Server: X.Org 1.16.4 drivers: nvidia,v4l Resolution: 1280x1024@60.02hz
           GLX Renderer: Quadro NVS 285/PCIe/SSE2 GLX Version: 2.1.2 NVIDIA 304.125
Audio:     Card Intel 82801H (ICH8 Family) HD Audio Controller driver: snd_hda_intel 
           Sound: Advanced Linux Sound Architecture v: k4.1.8-desktop-1.mga5
Network:   Card: Realtek RTL8111/8168/8411 PCI Express Gigabit Ethernet Controller driver: r8169
           IF: enp3s0 state: up speed: 1000 Mbps duplex: full mac: 00:18:f3:0a:2c:3b
Drives:    HDD Total Size: 580.1GB (70.5% used) ID-1: /dev/sda model: MAXTOR_STM380811 size: 80.0GB
           ID-2: /dev/sdb model: WDC_WD5000AAKS size: 500.1GB
Partition: ID-1: / size: 12G used: 5.1G (46%) fs: ext3 dev: /dev/sdb2 
           ID-2: /home size: 18G used: 11G (61%) fs: ext3 dev: /dev/sdb3 
           ID-3: swap-1 size: 4.30GB used: 0.00GB (0%) fs: swap dev: /dev/sdb1 
RAID:      No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors:   System Temperatures: cpu: 64.5C mobo: 53.0C gpu: 74C 
           Fan Speeds (in rpm): cpu: 4383 psu: 0 sys-1: 0 sys-2: 0 
Info:      Processes: 166 Uptime: 6 min Memory: 1619.7/3449.5MB Client: Shell (bash) inxi: 2.1.96

These sort of issues have been around for years and are well known with grub legacy.
They are BIOS dependant and are virtually impossible to resolve.

When multi-booting I would always recommend using a single very small partition with it's own installation of grub. Grub2 preferably.

The BIOS always boots this partition which runs it's own grub2 menu.
This menu is hand made and _never_ updated by any operating system. It simply chainloads into whichever OS is selected.

Each OS would be configured to only update it's own partitions and not write to the MBR of any drive.

If you would like to test this in principle by creating a grub2 boot CD, DVD or USB stick (rather than using a HD partition) then there is a script here that should create one for you. https://wiki.mageia.org/en/User:Barjac Note this is for PC-BIOS only NOT UEFI.

Hello Barry,
I agree it is virtually impossible to resolve with Grub Legacy at installation,
but about my second case A2) when kernel upgrade is made?
and about my third case B1) installation with Grub2?

Changing version back to 5. This is not an installer problem, it's a problem
with installing new kernel versions in an already installed system.

In the installer, when selecting sdb as the place to install the boot loader,
it asks which device will be used for booting.

Selecting sdb as the boot device, it correctly puts
(hd0) /dev/sdb
(hd1) /dev/sda
in /boot/grub/device.map and uses (hd0,0) (for sdb1) in /boot/grub/menu.lst.

When installing a new kernel, device.map gets changed to
(hd0) /dev/sda
(hd1) /dev/sdb
and it uses (hd1,0) in menu.lst for the new kernel.

I've occasionally forgotten to fix device.map and menu.lst on a new kernel
install, resulting in https://bugs.mageia.org/show_bug.cgi?id=16655#c42

I think the correct fix would likely be for the kernel-install to check whether
or not /boot/device.map already exists, and if it does, assume it's correct,
though that would require extensive testing to ensure it does not break new
installations.

Version: Cauldron => 5
CC: (none) => davidwhodgins

Changing back to cauldron, as it's likely affected too, and adding
MGA5TOO.

Whiteboard: (none) => MGA5TOO
Version: 5 => Cauldron

Created attachment 8015 [details]
grub: only update devices.map when installing grub

Created attachment 8016 [details]
grub: only overwrite install.sh when installing

Do those patches help?
You can try them by applying them as root in a terminal (assuming you downloaded them in /tmp):

cd /usr/lib/libDrakX
patch -p2 </tmp/0001-grub-only-update-devices.map-when-installing-grub.patch  
patch -p2 </tmp/0002-grub-only-update-devices.map-when-installing-grub.patch

Keywords: (none) => NEEDINFO, PATCH

> patch -p2 </tmp/0002-grub-only-update-devices.map-when-installing-grub.patch

This line being meant as:

patch -p2 </tmp/0002-grub-only-overwrite-install.sh-when-installing.patch

indeed

*** Bug 17000 has been marked as a duplicate of this bug. ***

CC: (none) => luigiwalser

There was no feedback from the reporter or anyone else on the proposed patches from five years ago.
Also, the reporter and the reporter of the duplicate bug both used grub legacy, which has become rare.

Closing as OLD

CC: (none) => marja11
Status: NEW => RESOLVED
Resolution: (none) => OLD

Hopefully the patches got committed.