Question regarding GRUB

thekid · 10-10-2007, 06:21 PM

I'm coming from Slackware, which uses LiLo, to Ubuntu, which uses GRUB, and I had some difficulty getting things setup. Finally I got it all working, but I'm curious about something. The pertinent part of menu.lst is:

Code:

title		Ubuntu, kernel 2.6.20-16-generic
root		(hd0,0)
kernel		/boot/vmlinuz-2.6.20-16-generic root=UUID=fea4a51a-3d61-45ca-991f-0d736333016a ro quiet splash noapic
initrd		/boot/initrd.img-2.6.20-16-generic
quiet
savedefault

title           WinXP
root            (hd1,0)
savedefault
makeactive
map             (hd0) (hd1)
map             (hd1) (hd0)
chainloader +1

Note that GRUB is set to look for Ubuntu on hd0 and XP on hd1, but when I do

Code:

keith@Krypton:~$ sudo grub
Probing devices to guess BIOS drives. This may take a long time.

grub> find /boot/vmlinuz-2.6.20-16-generic
 (hd1,0)

Am I missing something here? Shouldn't it be hd0? My setup is Ubuntu on a Sata dive, and XP on an IDE drive.

Brian1 · 10-10-2007, 07:00 PM

Post the output from ' /sbin/fidsk -l ' as root.

Brian

syg00 · 10-10-2007, 07:04 PM

Do they both boot ???.
Let's have a look at /boot/grub/device.map

thekid · 10-10-2007, 09:19 PM

Code:

keith@Krypton:~$ sudo /sbin/fdisk -l

Disk /dev/sda: 320.0 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        1216     9767488+  83  Linux
/dev/sda2            1217       13374    97659135   83  Linux
/dev/sda3           13375       13617     1951897+  82  Linux swap / Solaris
/dev/sda4           13618       38913   203190120   83  Linux

Disk /dev/hdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdb1   *           1        3770    30282493+   7  HPFS/NTFS
/dev/hdb2            3771       30401   213913507+  83  Linux
keith@Krypton:~$

Yes, they both boot, and here's the device.map:

Code:

keith@Krypton:~$ gedit /boot/grub/device.map 
(hd0)	/dev/sda
(hd1)	/dev/sdb

Brian1 · 10-12-2007, 06:06 PM

Kind of at a lost.

Brian

pixellany · 10-12-2007, 06:57 PM

I am stabbing in the dark. I think it is possible that the mixture of ide and sata can cause confusion.

I would be curious what the "find" command would say if you did it during startup. Reboot and, when the grub screen comes up, hit esc to stop the countdown (possibly esc again to get to text mode), and then "c" for a command prompt. Do the "find" thing from there.

syg00 · 10-12-2007, 08:41 PM

And in addition to that, "root (hd0,<tab>" (tab completion for partitions). The number will tell you which disk it is seeing as zero.

thekid · 10-12-2007, 11:24 PM

Interestingly enough when I ran the find command at boot it found vmlinuz on hd0...