[arch-dev-public] Load_Cycle_Count and storage-fixup

Paul Mattal paul at mattal.com
Sun Oct 18 19:51:49 EDT 2009


Roman Kyrylych wrote:
> On Thu, Sep 17, 2009 at 02:09, Xavier <shiningxc at gmail.com> wrote:
>> On Wed, Sep 16, 2009 at 10:09 PM, Roman Kyrylych
>> <roman.kyrylych at gmail.com> wrote:
>>> Hi all!
>>>
>>> I wanted to bring this long time ago when I discovered the problem
>>> with my old Seagate Momentus 5400.3, but then forgot
>>> since my new WD Scorpio Blue is less affected by this.
>>>
>>> But recently I noticed a couple of reports about the issue on forums and IRC,
>>> so I'm bringing this here.
>>>
>>> The problem is that on some HDDs (and/or with some BIOSes?)
>>> HDD head parking is done too often.
>>> This can be seen with Load_Cycle_Count in smartctl output
>>> being increased quickly (more than once per minute),
>>> and heard as relatively frequent clicks during low IO load.
>>> More at http://ata.wiki.kernel.org/index.php/Known_issues#Drives_which_perform_frequent_head_unloads_under_Linux
>>>
>>> Basically, if Load_Cycle_Count divided by Power_On_Hours is more than 30-60
>>> and your HDD is powered for many hours every day
>>> - your HDD may reach the limit in a couple of years.
>>>
>>> More info specifically about WD Green HDDs:
>>> http://kerneltrap.org/mailarchive/linux-kernel/2008/4/10/1396844/thread
>>> https://lists.ubuntu.com/archives/kernel-bugs/2008-April/035194.html
>>> (you can find wdidle3 with google, it's not accessible from WD site).
>>>
>>> I want to stress that this is _not_specific to WD Green drives.
>>>
>>> The problem is easy to fix, but that's if you _know_ about it.
>>> I think most of users are not aware of it.
>>>
>>> Now to the point of this message and why it is on this mailing list.
>>> What is the best way to handle this?
>>>
>>> There is a nice script which automatically tunes HDD options
>>> to fix this depending on HDD and/or laptop model.
>>> http://git.kernel.org/?p=linux/kernel/git/tj/storage-fixup.git
>>>
>>> Would it be okay if we package it and put it in core & install CD?
>>> Would it be enough to put this information in Official Install Guide?
>>> Would it be better to not care that much about this,
>>> and only mention it in some wiki page plus link in (Post-)Install Guide?
>>>
>>> I am really not sure what is the best way here.
>>> I'd like to hear your feedback on this.
>>>
>> +1 for spreading more the noise about this.
>> This was the opinion I expressed in this old thread :
>> http://bbs.archlinux.org/viewtopic.php?id=39258
>>
> 
> Anyone else has some opinion about how to handle this?

I'd like to affirm the opinions of Roman and Xavier and take some action 
on this.

Anyone object to my putting storage-fixup in [extra] at least? If no 
objections by W 9/21, I plan to go ahead with that step. If it works 
out, we can talk about follow-up steps like:

1) moving it to [core]
2) integrating it into default rc.d scripts

It's a pretty serious issue for laptop users with affected drives. And 
the drives are pretty popular ones, methinks.

I'm usually an Arch purist, and believe in not doing much for users 
aside from what they explicitly set up themselves-- but when it risks 
hurting their hardware, I revise my position slightly and want to have a 
discussion about doing something reasonable.

- P


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