Re: regarding crazy head unloads

[Tejun Heo <htejun@gmail.com>]

Bruce Allen wrote:
> Hi Tejun,
> 
> Sorry, this is a really really slow reply.  This email came at an
> unusually busy time and I did not reply before it got buried in the deluge.

Well, you were slow but I'm slower.  :-)

>> 2. This is from Roland.  Make smartd aware of the problem and warn user
>>    if load/unload count per powered on hours goes too high.  Maybe the
>>    warning can direct the user to linux-ata.org page?
> 
> It would be easy to implement this in smartd.  But I'm concerned about
> three things:
> 
>   -- most people don't run smartd (I think by default it is off on
>      the main Linux distros).  Those wise enough to run smartd will
>      probably be aware of the issue, since it's gotten lots of buzz. And
>      even if smartd is turned on in the distro it is normally not
>      configured to send warning emails.

We only have to hit one instance of each configuration where such
problem is occurring.  I think adding warning message out smartctl
output or letting smartd warn it to users via email or log messages
should be good enough for this problem.

>   -- I'm not sure if the attribute used for head load/unload is a standard
>      one.  On my current laptop Hitachi disk it is attribute 193.  Does
>      anyone know if this is standard?

I have no idea whatsoever.  Maybe implement a regexp matching on
attribute name?

>   -- I'm not sure at what threshold to send warning emails.  If we send
>      too many false alarms, they will be ignored by users.

To get it correct completely, I think we'll need per-device database.
Not easy....  :-(

Thanks.

-- 
tejun