How much research did you do on raid? My guess is NONE.
Here are the mistakes you have made:
-raiding twp partitions of the SAME disk
-trying to set up raid 5 with only two disks (which are actually 2 partitions of the same disk)
Basically you know nothing about raid, and you have only heard that it will work faster and be more reliable, right?
OK, now that I have gotten that off my chest, here is the helpful bit. Go to www.tldp.org
and search for the linux software raid HOWTO. It will, amongst other things, explain to you exactly what raid is and is NOT abaout, and it will guide you step by step through the setup process, and even the testing process.
and if you have any problems after reading that, post here and we'll sort them out quick sticks!!!