Re: RAID1, how to acivate booting ?

[Gerard W. Patterson]

On Thu, Nov 22, 2001 at 08:43:47AM -0500, Michael L - Cegonha Technologies 
wrote:
> Hi !
> 
>  I have recently install RedHat 7.2 with grub on one ide hard disk in Ext3
>  ... I have put 2 scsi hard drive to make a Raid 1, i would like to
>  transfer all my data on my new array, and i would like to remove my ide
>  disk, to use only the Raid Array.   I have succefully mount my aray to
>  /md0. See my partition table : 
> 
> My Ide Drive
>  /dev/dha1     /boot      30Mo 
> /dev/hda2     swap       512Mo
> /dev/hda3     /root        10000Mo
> 
> My boot scsi Drive 
> /dev/sda1    /boot      30Mo 
> /dev/sda2     swap       512Mo
> /dev/sda3     /root        8000Mo
> 
>  i have succesfully transfer data from my ide to md0 , but what can i do
>  for grub boot on my scsi ? 
> 
> thanks 
> 
> Michael 

I just finished setting up RAID1 with Grub. If you look a couple of postings
back you will see a discussing regarding this.

What I did was use a grub boot floppy and specify one of the drives as the
root device in the shell:

root (hd0)

I then specified the kernel image with the kernel parameter 'root=/dev/md0'
or what ever meta disk you are using as your root partition:

kernel /vmlinuz root=/dev/md0

After this, I typed:

setup (hd0)

This performed the rest of the install automatically.  Note this only will
setup the first hard drive of the array.  If the first drive fails and you
want grub to boot the second drive in the array you have to remove the first
drive from the array (after shutting down), boot from the floppy, and repeat
the above steps.

When I tried to replace the (hd0) with (hd1) and see if it would work, the
second drive wouldn't boot complaining about a 'hard disk error'  I am
guessing this is because it is looking for stage2 on the bios drive 0x81
which really isn't there since the second drive becomes the first drive 0x80
when the first drive fails.

Hope this helps!

Regards,

  Gerry
-- 
Gerard W. Patterson, B.Sc           |   Computalog Ltd.
Software Engineering                |   Edmonton, AB
<address@hidden>    |   Canada