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Comment by proactivesvcs | Hacker News Reader

I'm surprised to have read to the end and found that they're still not performing any hardware monitoring and alerting. SMART may not always show up pre-failure warnings but when it does they can usually be trusted.

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Wasn't it a conclusion of the Google hard drive reliability study that models based on SMART were not useful? I.e. drives with sector reallocations are much more likely to fail than those without, but their failure rate is still something like 15% per year, so what useful thing can you do with that signal?

Well I don't see why you'd want to keep running a drive that is showing warning signs, it's just asking for trouble. But even if one doesn't replace them from this data, if you start seeing alerts and at the same time your database suffers from corruption, that also shows the use of SMART.

Because taking drives out of service for SMART signals would cost a fortune and almost none of those drives were actually going to fail.

N=1, but I had a drive show catastrophic SMART failures once. I figured I'd take the opportunity to tinker with the exposed serial port on the drive's PCB and wiped the SMART values.

Funny thing was, I didn't actually observe any data loss. I stressed the drive for several days, no errors. It went back in my daily driver for the next 5 years with no failure. It's been 15 years since that happened and the drive still hasn't failed.

I don't trust SMART anymore.

I've known a fair few drives with uncorrectable sectors or adaptor warnings that continue to work but a lot more that have degraded or just outright failed.

Hard Disk Sentinel is really good for this type of thing. The developer is awesome and some years ago after I asked for some new features added code to better support my RAID adapter.

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