>Often you will read online of people experiencing multiple failures from drives purchased from the same batch
I'll toss in on that anecdata. This has happened to me a several times. In all these cases we were dealing with drives with more or less sequential serial numbers. In two instances they were just cache drives for our CDN nodes. Not a big deal, but I sure kept the remote hands busy those weeks trying to keep enough nodes online. In a prior job, it was our primary storage array. You'd think that RAID6+hot spare would be pretty robust, but 3 near simultaneous drive failures made a mockery of that. That was a bad day. The hot spare starting doing its thing with the first failure, and if it had finished rebuilding before the subsequent failures, we'd have been ok, but alas.
This has been the "conventional wisdom" for a very long time. Is this one of those things that get "lost with time" and every generation has to rediscover it?
Like, 25+ years ago I would've bought hard drives for just my personal usage in a software raid making sure I don't get consecutive serial numbers, but ones that are very different. I'd go to my local hardware shop and ask them specifically for that. They'd show me the drives / serial numbers before I ever even bought them for real.
I even used different manufacturers at some point when they didn't have non consecutive serials. I lost some storage because the drives weren't exactly the same size even though the advertized size matched, but better than having the RAID and extra cost be for nothing.
I can't fathom how anyone that is running drives in actual production wouldn't have been doing that.
It’s inconvenient compared to just ordering 10x or however many of the same thing and not caring. The issue with variety too is different performance characteristics can make the array unpredictable.
Of course, learned experience has value in the long term for a reason.
I had to re-learn this as well. Nobody told me. Ordered two drives, worked great in tandem until their simultaneous demise. Same symptoms at the same time
I rescued what could be rescued at a few KB/s read speed and then checked the serial numbers...
Nearly every storage failure I've dealt with has been because of a failed RAID card (except for thousands of bad quantum bigfoot hard drives at IUPUI).
Moving to software storage systems (ZFS, StorageSpaces, etc.) has saved my butt so many times.
Same thing I did except I only wanted WD Red drives. I bought them from Amazon, Newegg, and Micro center. Thankfully none of them were those nasty SMR drives, not sure how I lucked out.
I'll toss in on that anecdata. This has happened to me a several times. In all these cases we were dealing with drives with more or less sequential serial numbers. In two instances they were just cache drives for our CDN nodes. Not a big deal, but I sure kept the remote hands busy those weeks trying to keep enough nodes online. In a prior job, it was our primary storage array. You'd think that RAID6+hot spare would be pretty robust, but 3 near simultaneous drive failures made a mockery of that. That was a bad day. The hot spare starting doing its thing with the first failure, and if it had finished rebuilding before the subsequent failures, we'd have been ok, but alas.