SOLVED: grub2 on usb, no corresponding BIOS drive

[francois]

Trying to install grub2 on usb where I already had a grub legacy installation, I got the following error message:

Code: Select all

root@porteus:~# grub-install --no-floppy --root-directory="/mnt/tmp" /dev/sdb
/dev/sdb does not have any corresponding BIOS drive.

Googling on the net I did not found much direct information. Except that:
http://phoxis.org/2010/02/03/installing ... ootloader/
Check if the BIOS drive and device file mapping is correct. If it is correct then it is all successful. Else you need to fix the mapping and rerun the script, and probably if the mapping showed is wrong, some other partition’s boot sector which was wrongly mapped might be wiped out.
and hyperlink to a device map section:
http://phoxis.org/2010/02/03/installing ... er/#devmap
You can edit, or create or edit and add correct device mappings in such a device.map file manually, in "boot/grub" of the partition where you want to install grub and invoke grub-install.

Code: Select all

root@porteus:~# mkdir /mnt/tmp
root@porteus:~# fdisk -l
...
...
   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    15663103     7830528   83  Linux
root@porteus:~# mount /dev/sdb1 /mnt/tmp
root@porteus:~# grub-install --no-floppy --root-directory="/mnt/tmp" /dev/sdb
/dev/sdb does not have any corresponding BIOS drive.

Looking in /mnt/sdb1/boot/grub/device.map I had:

Code: Select all

(hd0)	/dev/sda
(hd1)	/dev/sdc

Changing for (hd1) /dev/sdb does the job:

Code: Select all

root@porteus:~# grub-install --no-floppy --root-directory="/mnt/tmp" /dev/sdb
Installation finished. No error reported.
This is the contents of the device map /mnt/tmp/boot/grub/device.map.
Check if this is correct or not. If any of the lines is incorrect,
fix it and re-run the script `grub-install'.

(hd0)   /dev/sda
(hd1)   /dev/sdb
root@porteus:~#