[colug-432] USB disks and Load Cycle Count

[Rob]

I have some 2.5" USB portable hard drives that I would like to press
into service as the main drive for several Pogoplug servers I have set
up locally.  These drives work fine, but when I run smartctl on them,
I'm seeing very high and rapidly increasing values for the SMART
attribute Load_Cycle_Count.  (Rapidly increasing means several thousand
instances per day.)  Load_Cycle_Count is an indication of how many times
the heads have been parked onto and then moved off their landing zone.
It seems the firmware in a lot of pocket drives automatically park the
heads if there has not been any disk activity for 5 seconds or so.  One
disk which had been pressed into service in January was showing over
250K head loads.

According to Wikipedia (the gold standard for unimpeachable data), a
typical lifetime rating for Load_Cycle_Count is 300-600K and when used
as I am using these disks many drives exceed their design limit within
the first year.  This self-parking "feature" may be fine when the drive
is carried around in a briefcase and only sporadically connected, but
it is decidedly detrimental in a lightly loaded server application where
there might be several disk accesses a minute.

My WD and Toshiba 2.5" drives seem to exhibit this behavior.  My
Seagates either don't, or don't report this statistic.  I suspect
the 3.5" drives are not so programmed, since it would be more typical
to use them in a fixed 24/7 configuration rather than as a portable
drive.

Has anyone else encountered this with drives you have used, and if
so, what did you do about it?  Is there a way to instruct the drive
to not park its heads automatically based on time in a quiescent state?

Thanks,
Rob