Re: Disk spin down issue on shut down/suspend to disk

[Tejun Heo <htejun@gmail.com>]

Mark Lord wrote:
> Tejun Heo wrote:
>> Michael Sedkowski wrote:
>>> Dnia 07-08-2007, Wt o godzinie 03:43 +0900, Tejun Heo napisał(a):
>>>> Does emergency unload count increase
>>>> after each power down? 
>>> I think I got it.
>>> Using smartctl I've done a test and shut down, then repeted the test.
>>> The only values that where diffrent are temperatures and
>>> Hardware_ECC_Recovered which rised by 6 points.
>>> However I have no idea which of those is the "emergency count"...
>>> Full results in attachment.
>>>
>>> 192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age  
>>> Always       -       388
>>
>> I think this is the one.  You can test it by forcefully powering off the
>> machine (press power button for several secs or disconnect AC and
>> battery) and see whether the count increases.
> 
> FWIW, Tejun, with 2.6.22, my new Seagate 160GB SATA drive (notebook)
> increments the "Power-Off_Retract_Count" on each suspend-to-RAM operation.
> It does not do any double spin-up/spin-down things though.
> 
> What a mess.

Hmmm.. It shouldn't.  libata now issues STANDBYNOW prior to entering
STR.  Can you instrument code a bit and see whether it actually gets issued?

Thanks.

-- 
tejun