Is disk really bad if mkfs.ext4 -c -c reports errors?

[Liam Proven]

On 11 January 2017 at 16:53, compdoc <compdoc at hotrodpc.com> wrote:
> Ive been actually repairing computers for the last 20 years, and I mean
> literally thousands of computers, and I stand by my statement. If SMART
> reports any number of reallocated sectors, or pending sectors, or a couple
> other errors I track, the drive has to be replaced. Anything else is voodoo.


Google says you're wrong.

I don't mean searching on Google. I mean Google, the company with the
biggest number of data centres and servers in history, says you're
wrong.

You think that Google & its research across a billion+ drives is wrong?

You would have to be foolishly brave to say that. And you're not even
brave enough to use your real name on a mailing list.

Here's the published paper:
https://research.google.com/pubs/pub32774.html

Quotation:
«
Our analysis identifies several parameters from the drive’s self
monitoring facility (SMART) that correlate highly with failures.
Despite this high correlation, we conclude that models based on SMART
parameters alone are unlikely to be useful for predicting individual
drive failures.
»

Your statement is too blanket and wide and your attempt to rephrase it
is not enough.

Yes, if a drive shows SMART errors, don't trust it and replace it
ASAP. On the other hand, try it and you might find it runs fine for
non-critical stuff for years to come.

But don't _rely_ exclusively on SMART, because drives can and do fail
without SMART warnings. Other signs to look out for:
* excessive drive noise, e.g. audible bearing whine
* repeated failure to initialise or lengthening of initialisation time
* failed reads or writes; often manifests as random filesystem corruption
* random pauses in operation, where the drive is retrying
* drive errors visible in the OS console

-- 
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