Use Backblaze's hard drive stats as a guide: https://www.backblaze.com/b2/hard-drive-test-data.html

I've yet to experience a failure of HGST drives, even after 10 years of operation in an LVM or ZFS array.

HGST remains my preference for "enterprise-y" stuff on home and small business setups. Slightly pricier but if you value your time it pays for itself easily.

I buy used 4TB HGST drives on eBay. They’ve all been solid and inexpensive, some with more wear and tear than the others.

I have a couple I'm looking to sell. Send me an email for the details.

Like my fellow commenter, I also do have a few drives with over 50k head hours on them that still work fine, but I also had probably more than half a dozen drives fail on me or break (not including Sandforce SSDs, that'd be unfair), including one that had all of my early projects on it. Really wish I had a backup of that.

Now I have a backup of everything and whenever I have to think about how much storage I need for something I always take that number and multiply it by three -- if it's only stored once or twice, it really can't be more important than /tmp.

Interesting for me, I’ve had two drive failures, both in the past year, but otherwise nothing for the past five+ years. Both were data center class drives (Seagate Exios) and died within the first 2 months of purchasing them. I have over 20 consumer grade drives with >50,000hrs of reported power on time, of which 3-4 are >70,000hrs. They constantly see writes, but I’m definitely not pushing max IOPs by no means on a regular basis. I’d say around 1-2% of the time they are under very heavy read/write activity, otherwise just constant appending of data at around 50Mb/sec across the entire RAID pool.

This is a pretty common pattern with disk failures - in my experience they either tend to fail in the first few months, or they make it for the duration.

It's even got a name: the bathtub curve[1].

[1]: http://www.applied-statistics.org/Glossary/BathTubCurve.html

Are you sure your data as stayed uncorrupted all this time? Another thing ZFS enables is detecting bitrot and corruptions (happening due to unexpected power loss or otherwise) that you otherwise may have been undetected but can still cause issues over time.

You are lucky, or bought the right brand of drives at the right time.

I had five new Seagate 7200.11s which had an easy life but not make it past 22 to 25k hours before they started failing en masse (and thats not even counting their firmware bug that got me). ZFS RAIDZ1 (RAID5) pool, which survived a second drive starting to fail while rebuilding from the first failure. It was that event that made me love ZFS forever.

Contrast to my WD Reds which are 52k+ hours without errors or issues (no failures in a set of 8). And some HGST refurb drives that are at 70k+ hours (some failures in a batch of 14, but they were refurb with wiped SMART data so the failures werent unexpected).

https://www.backblaze.com/blog/backblaze-hard-drive-stats-q2... has the best statistics that I know of. Basically a 1% failure rate each year (worse for a few bad batches of disks), so yes I think you have gotten lucky so far. (1 - .99^(25*3)) = 52% chance of at least one failure for three drives over 25 years.

Out of ~30 disks over my ~30 years of hard disks I can count at least 3 5.5" HDD failures and 5 or 6 2.5" HDD failures. Laptop drives seem to fail at a much higher rate especially for kids.

I was thinking the same thing. I still have two 2TB Ultrastar's that I bought re-furbished 5 years ago, and which have been running in various arrays for just about the entire time since then. knock on wood

I still have a 1.6gb IDE drive that is functional. I have drives with 70k hours that still run. I've had 2 drives fail in the last 30 years. It may be rare but when it happens you'll really wish you had a backup.