So I want to set up a server with Raid 1. The machine currently is running Ubuntu server and has a media drive that is shared with people in my house. I would like the media drive, all home folders and all my MYSQL databases on the raid array. I just bought 2 1.5 TB hard drives, and the plan was to reload the OS on these drives and set them up for raid 1. Both of my room-mates however tell me I should do this a different way. They say that I should keep the OS drive that I am currently using and just replace the media drive with the raid array.
My question is which set up is better? just replacing one drive with the raid array, or the whole system with the raid array. If I do the former, how will I ensure that my databases are on the array? Any suggestions or advice would be appreciated.