[ubuntu-uk] Load Unload Cycles

Dougie Richardson ddrichardson at btinternet.com
Thu Nov 1 14:05:53 GMT 2007


Hi Tom,

Samsung quote the load unload cycle threshold as 600000, so in your case
with such a high number of counts I'd be inclined to apply the
workaround.

There is a correlation on some drives but it depends on the
manufacturer. Hitachi and IBM use ramp or rollers to lift the heads from
the disk rather than impact on a landing zone.

As I understand it from Samsung's documentation, they use landing zones
or component start/stop zones. The idea is that when the drive powers
down the heads are landed on an area usually in the centre of the
platter that isn't writable, hence avoiding corruption.

It also isn't as simple as failure at the quoted threshold. The actual
figure is attained by testing and shows the minimum number of hits
landed before the chance of damage reaches 50% - in other words beyond
this threshold damage may occur but below it shouldn't.

The problem is that in a drive to improve power efficiency has caused
drives to be powered down more often, increasing the amount of counts.

On Thu, 2007-11-01 at 01:34 +0000, Tom Bamford wrote:
> I've been looking at this bug as well and peeked at my drive stats. The
> mentioned Load_Cycle_Count stands at 355,884 on my laptop after I
> observed it increase by over 150 counts in just a few minutes on battery
> power.
> 
> Can anyone confirm if there is a correlation between this count and the
> lifespan of a hard drive? I'm a little bit concerned my drive may be
> approaching retirement earlier than I'd hoped, especially as my current
> one is a replacement for an identical Samsung model that lasted only a
> few months from new, also running Ubuntu.
> 
> Tom
> 
> 
> On Wed, 2007-10-31 at 14:48 +0000, Dougie Richardson wrote:
> > Hi all,
> > 
> > While investigating the interesting arguments concerning bug #59695, I
> > noted that a lot of the argument centres around the assumption that
> > Windows bypasses BIOS settings and configures drive access with so
> > called "sane" values.
> > 
> > Well I thought I'd check this out and although I'm still in doubt as to
> > the validity of whether increased time spent in the hard disk landing
> > zone is significant in reducing lifespan - I can confirm one myth as
> > debunked: Windows Vista does not alter the load unload cycle parameters.
> > 
> > I've put up a quick piece on my blog (http://blog.lynxworks.eu/) but
> > suffice to say that after disabling in Ubuntu, after 15 minutes there is
> > no increase in load unload cycles. Reboot into Windows and after 15
> > minutes reboot to Ubuntu and surprisingly the cycles have increased by
> > ten.
> > 
> > Cheers,
> > 
> > Dougie Richardson
> > 
> > 
> 
> 




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