Apparently conflicting smartctl output

Janos Dohanics web at
Fri Jan 6 17:27:16 UTC 2012

On Thu, 05 Jan 2012 11:56:44 -0800
Chuck Swiger <cswiger at> wrote:

> On Jan 5, 2012, at 11:42 AM, Janos Dohanics wrote:
> > - Do I have a bad hard drive (apparently, I do...)
> > 
> > - Why are there "No Errors Logged" by smartctl?
> You've probably got a bad sector on the drive, anyway.
> The SMART error log is a funny thing governed by various drive's
> firmware which have quirks.  Some of 'em only have a self-test log,
> but don't store the error log at all; others will only record an
> error after they've given up trying to remap a failing sector.  You
> snipped too much of the smartctl output to see what the "Error
> logging capability" section says-- the full output would be more
> informative.
> You almost certainly want to do a full read-scan of the drive via "dd
> if=/dev/ad4 of=/dev/null bs=64k", which will help the drive notice
> any other failing sectors.  Repeat dd if it aborts early with an
> error (or add "conv=noerror", maybe).
> Regards,
> -- 
> -Chuck


Thank you - dd says:

dd: /dev/ad4: Input/output error
10025840+0 records in
10025840+0 records out
657053450240 bytes transferred in 5230.204427 secs (125626724 bytes/sec)

I have to replace this drive.

Janos Dohanics

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