A lot of people recommending against RAID 1 in this thread.
I concur that it should not be considered "Back up" but for the extra $80.00 of the cost of a 1.5TB internal HD these days, I am a firm believer of using RAID 1 for up time redundancy.
Hard drives are prone to failure, and when your main dirve with the OS< or even your internal data drive dies, you are immediately faced with some form of downtime.
You may have all your data safe on back up, you may even be one of the rare few that knows how to back up your OS install with all your changes and preferences in a way that you can easily restore it to a machine with a non bootable main HD,. but even in that case, you are S.O.L. right there and then until you procure your new drive, then once you get that new drive, you get to spend the better part of a day getting your OS back up and restoring everything before you can use the brick again. Some may not always be at leisure to lose that day/days getting things back up and running. Some may have the leisure, but are just smart enough not to want to waste that much time anyway when it can be prevented so damn easily.
RAID 1 means when a single hard drive fails, you can keep working while you wait for the new replacement drive to ship, , and rebuild the RAID when it is convenient to you. The Array rebuild is hands off, and fast and simple, easier than restoring an OS.
IMHO this is money in the bank, and a huge relief when a drive fails.
FYI, I have the spare drive sitting in a drawer ready if/when one of the drives on my DATA RAID 1 array dies,. (and of course it is also backed up to external drives.) so I can swap out a dead drive and get my redundancy back in under and hour. that can't be done without RAID 1 involved.
Christ for $80.00 how can you go wrong with that kind of up time guarantee?
. So I guess I'm one of those people that gets complacent and says "if it ain't broke don't fix it". Now this is only in regards to my OS drive. All of my data is now on an unRAID server which has a parity drive for redundancy and it then gets backed up to a second internal drive in my photo machine which then gets synced to an external that is stored off site. I guess I never worried about having to reload the OS and software but I can see how time would be saved.


