RAID1 is basically a mirror of the original disk.In this article i will be using these terms :-
1) Original HDD -> The default Disk on which your server OS is currently on.
2) Clone HDD -> Cloned from the original Drive
3) New Drive -> the one you have decided to make a raid drive.
3 drives of equal size (i am using 160GB x 3 drives)
make a copy of your original hard drive to another drive which we will call the "Clone HDD", you can use
many tools to clone your drive like bartpe, easeus disk copy, etc.
after creating a clone HDD from the original drive, remove the Original drive and only use it as a backup (if things get screwed up and you don't have a backup... :D ... you can rely on the original HDD to save your self.)
You have to convert the Clone HDD into dynamic disk to. right click on disk and select "Convert Disk to Dynamic"
Step by step installation screens of RAID1 after completing the pre-requisites
* Open -> Server Manager-> Storage -> Disk Management
First you need to attach another Empty HDD to the system and start the Disk Management. (make sure you delete any partitions on the new drive.
follow the same process if you have another multiple partitions on the Clone HDD to be Mirrored on the new drive.
Important :- During your testing i would suggest "DONOT" remove your clone drive to simulate a failure of a drive as, the failure would write the MBR on the raid drive and there would be some issues as the system would try and boot from the RAID1 rather than the clone. i was smart enough to test it out, but was lucky to have a backup prepared for a worst case scenario :P