Re: RAID on the root partition /

On Thursday June 15, talbotx@comcast.net wrote:

What I hope to be an easy fix.  Running Gentoo Linux and trying to setup
RAID 1 across the root partition hda3 hdc3.  Have the fstab set up to
look for /dev/md3 and I have built the OS on /dev/md3.  Works fine until
I reboot. System loads and states it can not find /dev/md3 and when I
look md3 not started.  I have MD as part of the kernel, I have
mdadm.conf setup like so:

DEVICE /dev/hda3 /dev/hdc3
ARRAY /dev/md3 level=raid1 devices=/dev/hda3,/dev/hdc3

What am I missing?

If that mdadm.conf is on the root filesystem, then obviously it is of
no value for setting up the root filesystem.

You can:
  - use an initramfs to do the work. Many distros do this for you.
    The mdadm source contains some notes and scripts that I use.
  - use a boot parameter of
         md=3,/dev/hda3,/dev/hdc3
    This is probably easiest, and as ide drives don't change their
    names this should be safe.

initramfs is best though.

NeilBrown