I’ve worked at a well known enterprise storage company. The biggest thing drilled into us was that we couldn’t trust anything reported to us by the hard drives. Hard drives can report back to the OS that the write succeeded even when it didn’t. When something like this happens you’re in for a world of hurt, especially over time. This isn’t a bad sector, it’s corrupt data.
My article was more geared towards home / small SMB users.
Silent data corruption will happen. Will you hit that at home? Probably not.
But maybe people should stop buying Synologies, QNAPS and all that kind of hardware, I don't know ;-)
How can you even begin to quantify this risk if you have no idea what the problem is, or if you’ve never actually checked? That’s irresponsible to tell people “nah you being run into this problem” or “Eh, RAID5 works great!” when you’ve never looked into the stats or supported people who end up getting all their data lost?
This is a real problem and anyone not running two drive redundancy in 2020 on data that they care about is going to lose their data eventually.
If they don’t care about the data, then sure it’s not a big deal. I myself have 2 Synologies where I back up one to the other. The backup Synology is raid 5 because I don’t care so much about losing data, but my main drive is RAID 6.
At the (tens of) thousands of drives scale (and where you treat drives as cattle) having some extra checks and balances for what you write is an excellent idea. Even better is doing that in a distributed way so multiple machines make that same decision. Occasionally you will run into a drive where the firmware has jumped the shark or some such. (Or CPUs or memory or bus issue for that matter).
But generally speaking drives DO know when they are returning bad data and will error before they will do that. The odds are about as good as other forms of hardware errors that will eat your data.