Clearing SMART errors I don't care about?

Tom Worster fsb at
Fri Dec 19 19:44:01 UTC 2008

On 12/19/08 12:38 PM, "Kirk Strauser" <kirk at> wrote:

> I beg to differ.  "smartctl -H /dev/ad8" says that it passes its self-
> assessment and doesn't expect the drive to flat-out die any day soon.
> I'd still like to know if the error count increased, or if it started
> to detect imminent failure.

there are plenty of hdd failure modes that smart can't predict. google's
monitoring of over 100,000 hdds over 9 months showed more than a third of
failures had no warning from smart.

so if my data matters, i need a robust hdd failure-tolerant system anyway,
i.e. raid (even if it's just gmirror, which i use for non-critical servers)
plus data snapshots to a remote site.

now, with that in place, what do i do with a smart warning? given that smart
algorithms are also prone to false positives, is there any benefit in
replacing the hdd now rather than waiting for it to fail and replacing it
then? not a great deal in my view.

but perhaps my raid array can't tolerate more than one hdd failure. i'd be
exposed to a second disk failure during the time to repair. if hdd failures
are independent (which i guess might not always be true) this isn't a big
concern. less of a concern than, for example, the chance of raid controller
failure, which i've seen happen. one time when that happened, the controller
corrupted all the disks in the array and when it was replaced rebuild was

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