Finally…I’ve gotten around to doing this. It has really taken a lot longer than it should have…but life is busy (I even went on vacation somewhere in there…AND stripped wallpaper/painted 2 rooms in the house. haha).
“Installing softRAID on Linux” is a more fitting title, at this point–being the Linux has been installed and working for quite a while, whereas the RAID has not.
I have changed my intended setup a few times during this journey, and have finally settled on leaving my /boot and /(root) partitions NON-raid, operating off of my /dev/sda drive. My home (which happens to be sda4) I have successfully converted to a dual disk raid 1 setup.
This document proved exceedingly helpful, I absolutely recommend it regardless of distribution. As everything was pretty much set up in my previous posts, all I did was add my entries to /etc/mdadm.conf using the command “mdadm -E –scan >> /etc/mdadm.conf” . After that, I did a rebuild of initcpio with this:
“[root ~]# mkinitcpio -g /boot/kernel26.img“. I also added my /dev/md2 into my fstab (along with the swap on the second drive).
With a reboot…everything worked magically. The only thing left for me to do was to reformat my single disk /home directory (sda4) to Linux raid auto detect (type “fd” using cfdisk), and then assemble the array. To do all this, I booted up from the Arch Linux live cd, changed the type of the partition, and then booted back into my normal setup. I was then able to run “mdadm -A /dev/md2 /dev/sda4” to add sda4 to the already running array md2. This started a rebuild of the array, syncing sda4 with sdb4. SUCCESS!
I am all done for now… maybe one day I’ll have the time to fiddle around with getting the root and boot partitions to work the same way…but until then, I am happy with what I’ve got. This was my end goal in the very beginning, anyway: to have a RAID backup for pictures and other important documents, which are stored in the /home directory.
Maybe someone will find this helpful, and save some time. It definitely did me good to take a break so I could observe some things I had done wrong (or incompletely).

CC