Yes, it covers exactly the "Then a drive fails spectacularly." case. Unless you were hit by some subtle silent data corruption across the RAID (but it's pretty rare compared to classic drive failure with buzzing and clicking sound).
> But it doesn't cover the your RAID controller dying
One of the reasons some people ditch the hardware RAID controllers and do everything in software. If you're at the point of pulling the drives from a dead enclosure and sticking them in something new it's really nice to not have to worry about hardware differences.
I agree, RAID is not a backup (and nobody said it is, in this thread). But if you self-host a lot of data, even as a hobby, it will make your life easier in case of disk failure.
I thought it was implied with "No RAID?" in response to data loss (wherein they mentioned that they had a backup :)
I'm personally very skeptical as I have been using/used RAID for 20+ years, and I have lost data due to:
- crappy/faulty RAID controllers: who actually spends money to buy a good hardware controller, when a cheap version is included in most Motherboards built in the last 15+ years? In one case (a build for a friend), the onboard controller was writing corrupt data to BOTH drives in a RAID-0, so when we tried to recover, the data on both drives was corrupt.
- Windows 8 beta which nuked my 8-drive partition during install
Just because it's in the name, doesn't mean it should be considered a fact or best practice in accordance with reality. I think this[0] reddit post frames it in the simplest way possible: "A backup is a copy of the information that is not attached to the system where the original information is."
There are many[1], many[2], many[3] articles about why "RAID is not a backup". If you google this phrase, many more people who are considerably more intelligent and wise than myself, can tell you why "RAID is not a backup" and it is a mantra that has saved myself, friends, colleagues and strangers alike a lot of pain.
The I used to stand for "inexpensive" too, until RAID drives turned out to be everything but. They've since made it a backronym as "independent", although the drives really aren't independent either.
Then a drive fails spectacularly.
And that's the story of how I thought I lost all our home movies. Luckily the home movies and pictures were backed up.