Software RAID on external USB disk: boot problems after upgrade to squeeze

[Panayiotis Karabassis <panayk@gmail.com>]

Hi!

To simplify things a little: I have an external USB disk (/dev/sdc1) 
that is part of an MD array (/dev/md0).

During boot, I experienced the following problem: /dev/md0 was assembled 
with only 1 drive out of 2 (the internal one). This was due to /dev/sdc1 
taking some time to be detected, i.e. being detected after /dev/md0 was 
assembled.

I had solved this in lenny by using the following 
/usr/share/initramfs-tools/scripts/local-top/mdadm script:

!/bin/sh
#
# Copyright © 2006-2008 Martin F. Krafft <madduck@debian.org>
# based on the scripts in the initramfs-tools package.
# released under the terms of the Artistic Licence.
#
set -eu

case ${1:-} in
  prereqs) echo "multipath"; exit 0;;
esac

. /scripts/functions

maybe_break pre-mdadm

# -----> local change here !!! <-----
sleep 13

if [ -e /scripts/local-top/md ]; then
  log_warning_msg "old md initialisation script found, getting out of 
its way..."
  exit 1
fi

MDADM=/sbin/mdadm
[ -x "$MDADM" ] || exit 0

...

My solution is broken after the upgrade to squeeze and the problem has 
regressed. Any insight appreciated!

Regards,
    Panayiotis