raid issues on Fedora 7

[Jeffrey Ross]

What am I missing when creating a raid 1 configuration.  I added a new 
disk to the system (/dev/sda) and put the old disk as /dev/sdb (these 
are SATA drives)

I built a new system on /dev/sda (/ = /dev/sda6, /var = /dev/sda5, 
/usr=/dev/sda6, /boot=/dev/sda1, and swap=/dev/sda3) and I left roughly 
300 GB for /home at /dev/sda7. 

I did the following:
fdisk and set /dev/sda7 to type fd  (/dev/sda7            2569       
48641   370081341   fd  Linux raid autodetect)
mdadm --create /dev/md7 --level=1 --raid-devices=2 /dev/sda7 missing 
(I'm planning to add /dev/sdb7 upon successful creation)
mkfs -V -t ext3 /dev/md7
e2label /dev/sdb2 /home1
e2label /dev/md7 /home
created a simple entry in /etc/mdadm.conf with "MAILADDR root"

next copied all my user data from /dev/sdb2 (my former /home partition)  
to /dev/md7.  This worked fine.

Then when I rebooted the system, /dev/md7 was gone and the system 
mounted /dev/sda7 as /home

Where did I go wrong?

Thanks, Jeff