Say I have 4 500GB hard drives, and I want two of them to be set up as a RAID 0 array to create 1TB. I want to do the same with the other 2 500GB drives (creating 2 1TB drives), but then I want to set these 1TB drives up in a RAID 1 array. Can that be done with the software RAID?
Yes, the software RAID can do 0+1. Here is an example from Apple. http://docs.info.apple.com/article.html?artnum=304377