grub problem

[Rashkae]

Luca Ferrari wrote:
> Hi all,
> I've got a problem with grub on a machine that has two disks on raid1. The 
> boot partition is on disk (hd0,1) and (hd1,1), I've checked that the 
> partitions are aligned. While the system was running I entered the grub 
> console and entered:
> root (hd0,1)
> setup (hd0)
> root (hd1,1)
> setup (hd1)
> 
> and then rebooted (the system tries to mount the /boot partition from the 
> /dev/md7 device), but grub hangs immediatly, just showing "Loading, please 
> wait...". I've tried booting from a live cd, opening a shell and disammbling 
> the raid device, then instrumenting grub to reinstall on one disk, but nothing 
> changed.
> Any suggestion on how to make this machine booting?
> 
>

You have a /boot partition... is that the first partition on those two
drives?

Also, make sure your hard drives are really where you think they are.
(hd0 and hd1.)  If they are SATA hard drives, it's possible to have them
 plugged into any arbitrary SATA port, and they are actually (hd4 and
hd5, for example)

And finally, if you boot from a Live CD and enter the grub console, I
would specify exactly what device I'm referring too.  It's entirely
possible (read: likely) for the bios to re-organize the order of hard
drives if you boot from an IDE optical drive then switch to SATA.

For example, use cat /proc/mdstat to verify which devices consists of
the md device my /boot is on, then, in grub

device (hd0) /dev/sda
device (hd1) /dev/sdb
root (hd0,1)
setup (hd0)
root (hd1,1)
setup (hd1)

Good luck.