I've used raid1 with mdadm tools but I think when I would do this again I'd take a look
at te devicemapper/ LVM
http://sourceware.org/dm/
http://sourceware.org/lvm2/
You want to make everything raid1? I left on both disks a part to boot without raid and when the
kernel is loaded it can mount the raid partition for the rest. by copying the small root partition to
the other disk and modifying the /etc/fstab file it is posible to you the other disk to book the
system.
I splitted the disks as I would do for a single disk. on the relevant partitions I made a raid
volume
# /etc/raidtab
raiddev /dev/md0
raid-level 1
nr-raid-disks 2
nr-spare-disks 0
persistent-superblock 1
chunk-size 4
device /dev/hda2
raid-disk 0
device /dev/hdb2
raid-disk 1
mkraid /dev/md0 builds the raid after that you can use /dev/md0 instead of /dev/hda2, you can copy this block a few times for every extra partitiion you want.
the commands you'll need are
raidstart raidstop
raidhotadd (to rebuild a raid, but the big disadvantage is that the new disk needs to have the
same partitions, as the old one, fdisk -l /dev/hda can help for this info.
good luck
Tlowk