Guys, a question about Raid 1

[jordan12]

I have an external box that supports Raid 1.

I have read here that Raid 1 is not considered a good backup solution.

If I am reading the right thing, it is saying that both drives are mirrored, so they have the same data. And if one drive dies, the other one will still be accessible and have your data

So once you replace the bad one, it rebuilds and you back in normal operation again.

How is this not a good backup solution?

 

[knothead34]

you sure what you read they were not talking about raid 0? only problem i see with raid 1 is ..if you get a virus its on the other drive to because its mirrored.......at least how i understand it. in my opinion out of the two most popular raid options raid 1 is the best.

 

[Concentric]

Don't think of it as "the second drive is an identical automatic backup of the other one".
Nevermind "not considered a good backup solution" - it's not a backup - fullstop (or period for you Americans).

The idea of RAID 1 is that every drive in the array is told to store exactly the same thing and changes are made to every drive at the same time.
So if you delete a file from the array volume (intentionally or otherwise), it's deleted on all the drives. That's not a backup, because you can't go and retrieve the file from the other drive(s) any more than you can from the first.
The same is true if the file is corrupted through a virus infection (cue an offline backup) or filesystem problems, or any other reason other than drive failure.

A backup would be a copy of the data held on another drive or array that is available for retrieval regardless of what happens to the primary copy.
For example, copying the data to an external drive and then storing that drive elsewhere.