Ominous smartd messages ....

Jon Radel jon at
Wed Aug 3 14:09:37 UTC 2016

On 8/3/16 10:00 AM, Brandon J. Wandersee wrote:
> Jon Radel writes:
>> I've read reasonable sounding commentary from people running very, very
>> large collections of hard drives that there is a high enough correlation
>> between this error and the drive going to heck sooner rather than later
>> that they take this as a sign to replace.  [Can't find reference right now.]
> While there's no way to know from the error message alone just what will
> happen to the disk in the coming days, the general reasoning is this:
> sectors are not physically segregated. They all sit on the same
> platter. Several bad sectors occuring in a short period might be a sign
> of physical fault in the platter, and if that fault is real then stress
> from the platter spinning will likely cause that fault to spread. So
> some people conclude that the appearance of several bad sectors in a
> short period should just be a signal to replace the disk immediately.

If I remember the discussion well enough (sad that I can't find it) my
use of "correlation" was precise.  They actually manage enough drives
(thousands) and kept enough records to allow for statistical analysis
which indicate that this smartd error correlates very well with failure
within [I wish I could remember] timeframe.

Do please excuse the utter lack of footnotes.  :-(

--Jon Radel
jon at

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