I have a linux server running, and it doesn't have raid.
I'd like to setup raid 1 on it.

Is it possible to take my existing server, add another HD to it and set up raid 1 so that non of my data would be lost?

Or would it be better to just add two new HDs and setup raid 1 on them and mount them? Then put my important data on the raid mount.

I'd really just like to take my existing server and setup RAID 1 with the existing disk.
I'm thining its not possible though.

Anybody have any thoughts, ideas?