Total novice question. I have a server that hosts websites, contains databases, etc. It has several hard drives in RAID arrays. If a disk fails, the server continues until a replacement disk is installed.
However, what if other component(s) fail like RAID controller, RAM, or whatever? Is it normal to just have a bunch of spare parts on standby?
I was wondering if an identical server would/could be set up to somehow be a mirror image of the other server. And that, if the primary server ever failed, we could switch to the other one without missing a beat.
Is this a normal backup strategy? If not, what is normal? If it is, how would it work to get the data from primary to secondary real-time?