Hi,
You are supposed to be able to setup the new drive as raid 1 right from the start, but it is not a bad idea to use the local backup as you mentioned. This way is actually a little safer in my opinion as it protects against some types of problems like accidental deletions, etc. The down side is that the local backup only allows you to do backups at the "folder" level. What this means is that however many folders you have in the root of Volume_1, you will have to schedule a backup of each one of them. This is not too big a deal if you are able to group all of your data into just a few folders, but the more folders you have to backup the more you have to schedule, if you understand what I mean. If you can group everything into say, videos, photos, and music, it should work ok. The only other option I can think of is to use some "external" backup software to like "syncback" to backup Volume_1 to Volume_2. It depends on your setup. Anyway, good luck.