grub failure to update MBR (using RAID and LVM)

[Paul Pianta]

On Thu, 2005-02-17 at 14:46 -0500, Shawn Iverson wrote:
> Greetings again,
> 
> I have yet another issue with my server.  I cannot update my GRUB menu.
> I have a RAID 1 set up as follows on FC3 with latest official updates:
> 
> /dev/hda, /dev/hdb, and /dev/hdc, with hda and hdb containing two
> mirrors and /dev/hdc as a hot spare.
> /dev/md0 is /boot with 1GB of space on and ext3 filesystem
> /dev/md1 is a linux LVM with a separate logical volume for each major
> mount point (/usr, /var, /, /home, etc.) using ext3 on a single volume
> group.
> 
> My BIOS settings are set to boot in this order:  IDE0, IDE1, IDE2.  I
> isolated the boot to IDE0 for the sake of troubleshooting this, though.
> Boot other devices is disabled.
> 
> Instead of getting the menu with the three choices, I still see my older
> menu containing only the two older kernels after rebooting.  I never had
> this much trouble with a boot loader before, and I am even considering
> switching it over to LILO because it seems to handle software RAID so
> much better, that is, if I cannot resolve this issue.

Hey Shawn 

I have run into this problem b4 too. Check out 'Step 25' at this
link ...

http://togami.com/~warren/guides/remoteraidcrazies/

You can also verify if grub is 'really' installed on your disks by doing
a 'dd if=/dev/hda bs=512 count=1' on each disk.

If grub is really installed you should see something like this - 

---snip---

[root at trinity root]# dd if=/dev/hda bs=512 count=1
�м؎�|�8u
�u�|tAʀ�|1؎м @|<t�y}�tTAU�ZRrIUuCA|��t7fL|�fD|��f�pf1 DfD
B�rp�s
�|�f at fD1���@��ffD|f1�4T
f1�tT
D
�L ;}<T
�ъl
Zt
p�۸�r*ÎH|`�1a&B|}��}��}�}��GRUB GeomHard DiskRead Error�<u��v?
?/
�~}
KK4�LL#/-U1+0 records in
1+0 records out

---snip---

Don't worry about the diskread error message - its ok - it means that
grub is installed there. If grub is not installed you will see something
like this ...

---snip---

[root at trinity root]# dd if=/dev/hdc bs=512 count=1
м؎�|�8u
�u�|tL��|�?
?/
�~}
KK4�LL#/-U1+0 records in
1+0 records out

---snip---

It's a really annoying 'bug' with anaconda? that grub is not written to
all disks when a RAID setup is configured during installation ...

Hope that helps :)

pantz