Thanks a lot for your advices. I tried to install grub on both sda and sdb but without success.
However I found a workaround and a possible guilty : - switching to UEFI and installig grub-efi does work. I still have a "efidisk read error" which is non-blocking because grub stage2 menu starts immediatly after displaying this - therefore the guilty seems to be the BIOS. If you confirm this point, feel free to close the bug. ___________________________________________________________ Qu'y a-t-il ce soir à la télé ? D'un coup d'œil, visualisez le programme sur Voila.fr http://tv.voila.fr/programmes/chaines-tnt/ce-soir.html -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org