The Ubuntu Live CD installer doesn't support software RAID, and the server and alternate CDs only allow you to do RAID levels 0, 1, and 5. Raid 10 is the fastest RAID level that also has good redundancy too. So I was disappointed that Ubuntu didn't have it as a option for my new file server. I didn't want shell out lots of money for a RAID controller, especially since benchmarks show little performance benefit using a Hardware controller configured for RAID 10 in a file server.
I'll asume you have already known about RAID 10, but I'll cover a some important information before you begin.