I assume you already have success booting directly into a RAID configuration
from a floppy disk. If not, that would be a good thing to get working
before trying anything more complicated and will give you a backup process
in case your version of LILO doesn't do the entire job.
I have no experience with the Mandrake distribution; but like some others
including Redhat, I believe that it comes with a patched version of LILO and
probably also has the newer alpha RAID patches as well.
With the newer versions of LILO, you can include a line:
boot=/dev/md0
in place of your existing reference to /dev/hda, then LILO will write the
boot loader to each drive in the RAID-1 array.
Even with this in place, you may not be able to boot your PC with the
primary hard drive (hda) missing or non-functional - that will depend on
your BIOS and IDE hardware. In a failed IDE drive situation, one would
normally assume that the mirror drive would have to be physically
reconfigured to appear as HDA before you could boot directly from it.
Prior emails on the linux-raid mailing list have discussed this in detail,
you might search for it at:
http://www.mail-archive.com/linux-raid@vger.rutgers.edu/
Rich Bollinger
----- Original Message -----
From: "Michel Dagenais" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Tuesday, August 01, 2000 11:24 AM
Subject: boot=/dev/mdX
>
> Hi, I checked all the relevant latest HOWTO, LILO documentation, and
> searched deja.com but could not find any information about the recent
> ability of LILO for booting from RAID drives. I would like my system to
> still boot even if one of my two ide "RAID 1" drive fails. It is not
> clear from the LILO 21.4.3 source code exactly how to obtain this result.
> Would simply boot=/dev/md0, root=/dev/md1 do the trick? The relevant
details
> of my system are below. If you could give me a few hints, it would be
> most appreciated and i would gladly communicate my experience with this
> "typical RAID1 setup" to the HOWTO maintainers. Thanks!
>
> This is a new system with two mirrored (RAID1) ide disks and
> /boot, /, /home, /home2 and swap on md0(hda1, hdc1), md1(hda5, hdc5),
> md2(hda6, hdc6), md3(hda7, hdc7), md4(hda8, hdc8). The latest HOWTO i
> could find (20th july 2000) still says "LILO does not know about
> device 0x9??",
(ftp://ftp.bizsystems.net/pub/raid/Boot+Root+Raid+LILO.html),
> yet Mandrake 7.1 succeeded installing LILO with
>
> boot=/dev/hda
> image=/boot/vmlinuz-smp
> label=linux
> root=/dev/md1
> read-only
>
> Indeed, while there is nothing in the LILO documentation, the source
> contains code for RAID. From what i understand, root=/dev/md1 takes the
> first available disk and obtains the relevant block list. If hda breaks
> down there is no boot sector on hdc. If i put a boot sector on hdc
> as well, will image=/boot/vmlinuz-smp on the md0 partition lead to the
> blocs on the hdc drive...
