Re: Disk clicking and in increasing Load_Cycle_Count in laptop with debian/testing
On Sat, 14 Apr 2012, wzab wrote:
> When left unused, after the screen gets black to save power, the disks
> starts to click every few minutes, and after each click the
> Load_Cycle_Count (as reported by smartctl -a /dev/sda ) increases by
> 1.
...
> I have found the website:
> http://www.thinkwiki.org/wiki/Problem_with_hard_drive_clicking ,
> which describes the same or similar problem, but it seems, that
> solutions described there do not help.
>
> What's interesting - when I tried to run the following command (from
> remote console via ssh, so that the screen remains black):
>
> # ( LANG=C; while true ; do date ; smartctl -a /dev/sda | grep
> Load_Cycle ; sleep 10 ; done ) > /tmp/rep
>
> to find how often the head get unloaded, I have completely prevented
> this effect to occur.
Well, you'd be keeping the disk _and the SATA link_ busy.
Now, usually hdparm -B 254 can convince the disk to not be so silly as to
destroy itself too fast in an attempt to save power, and you've already
covered that one. So the next probable cause is SATA link power management
causing the disk to decide that, since its PHY is down, it might as well
unload the heads...
> It is really allarming, as with warranted durability of 600 000
> load/unload cycles, at this rate my drive will survive only ca. 3
> years!
>
> I've verified, that the set APM level remains untouched (e.g. when
> set to 254, and after 20 minutes reported by "hdparm -I /dev/sda":
> Advanced power management level: 254 )
Disable SATA link power saving. Does that fix the problem? If it does,
maybe a less aggressive level of SATA link power saving might also do the
trick.
Failing that, you can either disable SATA link power saving entirely and
waste power, or start a hunt (maybe with the help of blocktrace, or the
recently released LTTng 2.0 toolkit), to get rid of every crap that pesters
the disk at regular intervals while the box is idle.
Alternatively, you could also make sure something pesters the disk often
enough for it to not unload heads.
If it is not SATA link power saving, I am out of ideas.
--
"One disk to rule them all, One disk to find them. One disk to bring
them all and in the darkness grind them. In the Land of Redmond
where the shadows lie." -- The Silicon Valley Tarot
Henrique Holschuh
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