Short SMART check causes disk op timeouts

martinko gamato at
Mon Oct 27 12:50:53 PDT 2008

Jeremy Chadwick wrote:
> On Mon, Oct 27, 2008 at 07:52:01PM +0100, martinko wrote:
>> Jeremy Chadwick wrote:
>>>>>> Now, does the timeout cause loss of any data? Is there anything besides
>>>>>> disabling the testing that I can do about it?
>>>>> Do you understand what short and long offline tests actually do and what
>>>>> they're used for?  :-)  If so, you'd know that running them periodically
>>>>> is more or less silly (IMHO).
>>>> I do not, not completely :) I think I have just copied the settings from
>>>> somewhere and only just tweaked it a bit whenever I have added a disk.
>>> Let me know if you figure out who or what online resource solicited
>>> adding daily short/long tests, as I'd like to talk to them about their
>>> decision.  I have a feeling whoever thought it up felt that the tests
>>> were performing entire sector scans of the entire disk, which is simply
>>> not the case.
>> Hallo,
>> Reading this thread I checked my config to find this: ;-)
>> #/dev/ad0 -a -n standby,q -o on -S on -s (S/../.././02|L/../../7/03) -m  
>> root    # ++ 2006-11-03 mato
>> /dev/ad0 -a -o on -S on -s (S/../.././02|L/../../7/03) -m root  # ++  
>> 2006-11-03 mato
>> I believe I came up with the settings after reading manual page /  
>> documentation of the tool.
> Can you explain why you're doing this?  So far no one's provided a
> reason *why* they're doing short and long offline scans on a daily
> basis.  I'm under the impression the conclusion was reached like this:
> "man smartd.conf ... oh, -s, a neat thing, let's enable it".
> There are negative repercussions to doing tests of this nature at such
> regular intervals.  Once-a-week is borderline acceptable; once a month
> would be quite reasonable.  I'd love to know what kind of affect daily
> tests have on MTBF; I can imagine it's reached much sooner with this.
> The main point of smartd is to monitor SMART attribute changes.  If
> you're concerned about the health of your hard disk, you should be
> looking at your logs and not relying on things like automatic short/long
> tests.  Most SMART attributes are updated immediately and not during an
> offline test, and all of those attribute changes will be logged.

You asked Miroslav about source of his configuration.  And as it is very 
similar to mine I think we both have it from smartd documentation. 
Where else to look for information?  It's a usual source.  So if you 
think it's wrong please contact the authors, we're obviously just users.


PS: Btw, long offline scan is scheduled on weekly basis, not daily. If 
it's good or not I do not know.

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