[ltp] hdparm -B 1 and Load_Cycle on Hitachi HTS541616J9SA00

[Marc MERLIN]

Howdy,

So I had read about the hdparm -B 1 problem that caused a lot of
load/unload cycles on some drives, and put a lot of wear on drives.

I never really worried about it because I tought it caused the drive to
spin down and spin back up, which I can definitely hear, but wasn't
happening on my drive unless I'm on batteries with laptop-mode, where it
then does spin up and down from time to time, but not that often.

Yet, I just ran this:
gandalf:/etc/acpi# smartctl -A /dev/sda | grep Load_Cycle
193 Load_Cycle_Count        0x0012   047   047   000    Old_age   Always -       537975

and found out that I was very close to the 600,000 Load Cycle limit,
after which some say drives can start to fail.

Yet,
1) before I stopped this with hdparm -B 254 /dev/sda, I positively know
that my drive was not spinning down and up all the time, even if the
Load_Cycle_Count was increasing every second, even with laptop-mode
disabled and power plugged in.
It looks like my /etc/acpi/power.sh, or something else is buggy, and 
hdparm -B 255 was not being run when the power was restored, so my 
Load_Cycle_Count went up every second, even when the laptop was plugged in.

2) a comment on https://bugs.launchpad.net/ubuntu/+bug/104535/comments/8
says "Just to let you know: Hitachi uses quite special own technology to
park HDD heads outside of magnetic disks area to a special parking ramp.
This causes HDD heads not to suffer from parking - they're NEVER land on
disk surface during parking. So, actually, Hitachi HDDs can handle a
LOTS of starts\stops without any real problems"
And I indeed have a Hitachi disk: HTS541616J9SA00

My questions are:
1) why was my load cycle going up so quickly without the disk spinning
down?
2) Given all the info above, is my disk almost dead?
3) Any idea why Load_Cycle_Count would go up every second when the drive
really did not seem to be spinning down and back up?

Thanks
Marc
-- 
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Microsoft is to operating systems & security ....
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Home page: http://marc.merlins.org/