bug about “grub-installer” on raid, install with ubiquity. Possibly related to bug #936115?

[SoftLibre]

At the conclusion of the SO install, grub is not able to run "grub-install /dev/mapper/pdc_caahdjahe"
Choose the partition you choose, always gives error

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: ubiquity 2.9.21
ProcVersionSignature: Ubuntu 3.2.0-17.27-generic 3.2.6
Uname: Linux 3.2.0-17-generic x86_64
ApportVersion: 1.93-0ubuntu2
Architecture: amd64
CasperVersion: 1.304
Date: Sat Feb 25 21:20:35 2012
InstallCmdLine: noprompt cdrom-detect/try-usb=true file=/cdrom/preseed/ubuntu.seed boot=casper initrd=/casper/initrd.lz quiet splash -- debian-installer/language=es keyboard-configuration/layoutcode?=es
LiveMediaBuild: Ubuntu 12.04 LTS "Precise Pangolin" - Alpha amd64 (20120225)
ProcEnviron:
 LANGUAGE=es_ES.UTF-8
 TERM=unknown
 PATH=(custom, no user)
 LANG=es_ES.UTF-8
 SHELL=/bin/bash
SourcePackage: grub-installer
UpgradeStatus: No upgrade log present (fresh install)

[SoftLibre (softlibre-gmail)]

With a usb-live, it's ok :-D
*********************************************
ubuntu@ubuntu:~$ sudo mount /dev/mapper/pdc_caahdjahe2 /mnt
ubuntu@ubuntu:~$ sudo mount --bind /dev /mnt/dev
ubuntu@ubuntu:~$ sudo mount --bind /dev/pts /mnt/dev/pts
ubuntu@ubuntu:~$ sudo mount --bind /proc /mnt/proc
ubuntu@ubuntu:~$ sudo mount --bind /sys /mnt/sys
ubuntu@ubuntu:~$ sudo chroot /mnt

root@ubuntu:/# sudo update-grub2
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.2.0-17-generic
Found initrd image: /boot/initrd.img-3.2.0-17-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Linux Mint 12 Lisa (12) on /dev/sdc1
Found Windows 7 (loader) on /dev/mapper/pdc_caahdjahe1
Found Ubuntu 10.10 (10.10) on /dev/mapper/pdc_dffabaibi1
grep: el fichero de entrada `/boot/grub/grub.cfg.new' también es el de salida
done
root@ubuntu:/# grub-install /dev/mapper/pdc_caahdjahe
Installation finished. No error reported.
root@ubuntu:/#
*********************************************

[SoftLibre (softlibre-gmail)]

It has not worked.
I think the problem is that it does not create the devices correctly.
Assistant boot message.

[SoftLibre (softlibre-gmail)]

I compared the devices created in the session "usb-live" with those obtained in the partition on which I installed.

[SoftLibre (softlibre-gmail)]

Another detail.

Hope this helps. Thank you very much.

[SoftLibre (softlibre-gmail)]

Tested again with the daily image, which should correspond to the beta1
precise-desktop-amd64.iso 02-Mar-2012 07:56

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Christophe CATARINA (christophe.catarina)]

Not sure it is the same PB, but :
- ISO alternate 12.04 beta1, AMD64
- install on 2HD - RAID 1 + LVM (3 LV for /, /home + swap)
Installation failed at end, on "grub-install"

I have noted than the command try to install grub only on 1 disk ("grub-install /dev/sdb").
When the choice is proposed, I have asked for "boot even if one disk failed".
In this case (as far as I remember) the grub install command should try to write on both disk (grub-install /dev/sda /dev/sdb)