#  http://www.debian-administration.org/articles/238
#
#  /dev/sda == original drive with data
#  /dev/sdb == new 2nd drive.
#
apt-get install mdadm
#    Ansers during install:
#    Arrays needed to boot system:
#    	all
#    Should mdadm run monthly redundancy checks of the MD arrays? 
#   	yes
#    Do you want to start the MD monitoring daemon?
#       yes
#    Recipient for email notifications: 
#       5103053800@mobile.mycingular.com
#   Config file: /etc/mdadm/mdadm.conf


# change the system types on partitions to fd
sfdisk -l /dev/sda
#      Device Boot Start     End   #cyls    #blocks   Id  System
#   /dev/sda1   *      0+     11      12-     96358+  83  Linux
#   /dev/sda2         12   38672   38661  310544482+  83  Linux
#   /dev/sda3      38673   38912     240    1927800   82  Linux swap / Solaris
#   /dev/sda4          0       -       0          0    0  Empty

#
#  change partion type of sda1 and sda2 to fd
#
fdisk  /dev/sda
p
t
1
fd  # Linux raid auto
2
fd  # Linux raid auto
w

# List 
sfdisk -l /dev/sda
#      Device Boot Start     End   #cyls    #blocks   Id  System
#   /dev/sda1   *      0+     11      12-     96358+  fd  Linux raid autodetect
#   /dev/sda2         12   38672   38661  310544482+  fd  Linux raid autodetect
#   /dev/sda3      38673   38912     240    1927800   82  Linux swap / Solaris
#   /dev/sda4          0       -       0          0    0  Empty

# use sfdisk to duplicate partitions from old drive to new drive:
sfdisk -d /dev/sda | sfdisk /dev/sdb
sfdisk -l /dev/sdb
#      Device Boot Start     End   #cyls    #blocks   Id  System
#   /dev/sdb1   *      0+     11      12-     96358+  fd  Linux raid autodetect
#   /dev/sdb2         12   38672   38661  310544482+  fd  Linux raid autodetect
#   /dev/sdb3      38673   38912     240    1927800   82  Linux swap / Solaris
#   /dev/sdb4          0       -       0          0    0  Empty

# Load raid1 module
modprobe raid1
echo 'raid1' >> /etc/modules

# Create device nodes
mknod /dev/md0 b 9 0
mknod /dev/md1 b 9 1

# create the raid arrays.
mdadm --create /dev/md0 --level 1 --raid-devices=2 missing /dev/sdb1
mdadm --create /dev/md1 --level 1 --raid-devices=2 missing /dev/sdb2

cat /proc/mdstat     
#
#    Personalities : [raid1]
#    md1 : active raid1 sdb2[1]
#          310544384 blocks [2/1] [_U]
#    
#    md0 : active raid1 sdb1[1]
#          96256 blocks [2/1] [_U]
#    
#    unused devices: <none>
#    

# create filesystems for the raid devices. 
mkfs.ext3 /dev/md0
mkfs.reiserfs /dev/md1

# make mount points
# mount the file systems
# copy over the data
#
umount /boot

mkdir /mnt/md1
mount /dev/md1 /mnt/md1
cp -dpRx / /mnt/md1

mkdir /mnt/md0
mount /dev/sda1 /boot/
rsync -az /boot/ /mnt/md0 
ln -s ./ /mnt/md0/boot
umount /boot
 
# Make swap partition
mkswap -v1 /dev/sdb3

#
# Edit /mnt/sdb2/etc/fstab
#
sed -i -e 's/sda1/md0/' -e 's/sda2/md1/' /mnt/md1/etc/fstab
echo '/dev/sdb3       none            swap    sw,pri=1                   0       0'  >> /mnt/md1/etc/fstab

# Should look like this at the end.
# /dev/md1                   /              reiserfs notail          0       1
# /dev/sda3                  none           swap    sw,pri=1         0       0
# /dev/sdb3                  none           swap    sw,pri=1         0       0

#  The "pri=1" for each of the swap partitions makes them the same
#  priority so the kernel does striping and that speeds up vm.

#
# Edit  Grub on the mirror
#
vi /mnt/md0/grub/menu.lst 
#
#############################################################
# RAID1 Config
#############################################################
title           Debian GNU/Linux, kernel 2.6.18-4-686 ( RAID1 )
root            (hd0,0)
kernel          /vmlinuz-2.6.18-4-686 root=/dev/md1 md=0,/dev/sda1,/dev/sdb1 ro
initrd          /initrd.img-2.6.18-4-686
savedefault

title           Debian GNU/Linux, kernel 2.6.18-4-686 ( RAID1 Recovery )
root            (hd0,0)
kernel          /vmlinuz-2.6.18-4-686 root=/dev/md1 md=0,/dev/sdb1 ro single
initrd          /initrd.img-2.6.18-4-686
savedefault
##############################################################

#
# Install grub on the second drive so if the first drive fails we can still boot.
#
#   grub-install --no-floppy --root-directory=/mnt/hdc1 /dev/hdc
grub-install --no-floppy --recheck /dev/sdb


grub  --no-floppy
grub
grub: device (hd0) /dev/sdb
grub: root (hd0,0)
grub: setup (hd0)
grub: quit

grub-install --no-floppy --root-directory=/mnt/md0 /dev/sdb
grub-install --no-floppy --root-directory=/mnt/md0 /dev/sda
#   /dev/sdb does not have any corresponding BIOS drive.

grub-install --recheck /dev/sdb

grub-install --no-floppy --recheck 
grub-install --no-floppy /dev/sda
grub  --no-floppy




#
# Copy grub and fstab to old system.
#
mount /dev/sda1 /boot
cp /boot/grub/menu.lst /boot/grub/menu.lst.non_raid
cp /etc/fstab  /etc/fstab.non_raid
cp /mnt/md1/etc/fstab /etc/fstab
cp /mnt/md0/grub/menu.lst /boot/grub/menu.lst