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

Roman Kyrylych roman.kyrylych at gmail.com
Wed Sep 16 16:09:12 EDT 2009

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:
(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.

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.

Roman Kyrylych (Роман Кирилич)

More information about the arch-dev-public mailing list