Thank you, now it seems to work :D
If not, I will report. What I did follows:
Code:
knoppix@1[knoppix]$ sudo mount  /media/hdb3
knoppix@1[knoppix]$ sudo grub-install --root-directory=/media/hdb3  /dev/hda
Due to a bug in xfs_freeze, the following command might produce a segmentation
fault when /media/hdb3/boot/grub is not in an XFS filesystem. This error is harmless and
can be ignored.
xfs_freeze: specified file ["/media/hdb3/boot/grub"] is not on an XFS filesystem
Installation finished. No error reported.
This is the contents of the device map /media/hdb3/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'.

(hd1)   /dev/hdb
(fd0)   /dev/fd0
(hd2)   /dev/sda
(hd0)   /dev/hda
knoppix@1[knoppix]$