Re: One drive which perform frequent head unloads under Linux

[Tejun Heo <tj@kernel.org>]

Vincenzo Ciancia wrote:
> On lun, 2008-09-29 at 17:44 +0900, Tejun Heo wrote:
>> Vincenzo Ciancia wrote:
>>> Hi, I own a toshiba m400 and I already had to replace a disk in less
>>> than one year (luckily, it was covered by warranty). I noticed that
>>> Load_Cycle_Count was indeed increasing. Using hdparm -B 255 fixes it,
>>> but also 254 seems to fix it (and I guess it is better to have some
>>> power management than none at all?). 
>>>
>>> I am not subscribed to the list so if you need more information just ask
>>> me. I followed instructions at
>>>
>>> http://ata.wiki.kernel.org/index.php/Known_issues#How_to_determine_whether_a_machine_has_this_problem
>> I just updated the page.  Can you please read the updated part (which is
>> in bold) and post how much the load cycle count increases per hour
>> without any adjustment?
> 
> The problem is that now I don't know what is the default (I also found
> no way to read the -B setting with hdparm). I tried with hdparm -B 128
> which seems adviced by many for laptops, and I get 130 cycles per hour. 

APM setting is not persistent and BIOS probably programs it during boot,
so just removing any script you added and doing a cold reboot should
give you the default configuration.

-- 
tejun