

Increasing head-parking interval from default on Western Digital drives (2014) - walterbell
https://forums.freenas.org/index.php?threads/hacking-wd-greens-and-reds-with-wdidle3-exe.18171/

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ChuckMcM
Nice writeup Walter. One of the more useful things about a static landing zone
is that the head isn't moving over a surface as it does on a traditional
center landing zone. Both Seagate and WD drives have had issues with drives
"kicking up" contaminants from the LZ which cause a head crash later as those
contaminants migrate across the surface of the disk.

As for lifecycle, I'm with atap who questions the limits on this plastic.
Basically there isn't anything to "wear out" as far as I can see on the
landing zone.

~~~
kw71
If there is any wear then I think it is microscopic. I had a Green disk die
after 45000 hours of spin time, over 1.5 million load cycles. I could not
visually see any defects on the loading ramp with a 5x lens. I think the
failure mode of this WD10EACS was one head started going bad.

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userbinator
540 _5_ RPM? I'd like to see a source on that. I did a search, and was
irritated to find only people on other websites parroting that number. The
Wikipedia article has it, but the citation is WD's own spec sheet which
doesn't mention any number.

Did someone take a non-contact digital tachometer to a (presumably dead)
opened one and measure it? 5405 is only 0.093% more than 5400 and within the
tolerance of the measuring device (and the HDD spindle motor also has its own
rotational speed tolerance.)

Edit: found this benchmark using a software that appears to estimate spindle
speed, and it basically shows it as being a 5400RPM drive:

[http://www.hkepc.com/forum/archiver/?tid-1562968.html](http://www.hkepc.com/forum/archiver/?tid-1562968.html)

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walterbell
The WDIDLE3 executable can be found at
[http://support.wdc.com/product/download.asp?groupid=609&sid=...](http://support.wdc.com/product/download.asp?groupid=609&sid=113)
or bundled with a bootable DOS image on the Ultimate Boot CD,
[https://www.ultimatebootcd.com/](https://www.ultimatebootcd.com/)

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jleahy
You can also use idle3-tools on Linux to do this, which saves having to reboot
into DOS. It's even packaged for Debian/Ubuntu.

$ sudo apt-get install idle3-tools

$ sudo idle3ctl -s 138 /dev/sdx (for 300 seconds)

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atap

      > To make problems even worse, that landing 
        zone is only rated for 250,000 to 350,000
        cycles or so.
    

I don't understand how a little orange plastic widget suffers damage or
delivers damage to the drive heads during a head parking procedure.

It really doesn't seem like parking the drive heads would be an action that
requires any kind of contact or friction between moving parts.

What's different about parking near the rim, instead of near the spindle?

~~~
Sanddancer
Eliminating drag. Because the head uses air pressure to keep itself off the
platter, that air is also going to be pressing against the drive, causing
friction, and requiring the motor to work a bit harder. By parking away from
the platter altogether, you're eliminating that source of drag and friction.
Regarding the orange widget, the damage happens over hundreds of thousands of
park and unpark cycles -- a little wobble and a little rubbing after each one,
which will eventually be enough to get things out of alignment and thus,
broken.

The difference between near the rim and near the spindle is that air pressure.
If it's near the spindle, it still has that drag that's making the motor work
harder. Near the rim, that pressure is gone.

~~~
atap
It just seems strange that there needs to be an orange widget to act as a
"landing zone" at all.

Why not park the heads hanging in free space? Ostensibly the plastic widget is
probably a guide rail to prevent head crashes, when the head unparks onto a
platter spinning at full speed?

~~~
rzzzt
There's a short whitepaper published by HGST (now part of Western Digital)
which discusses the history and benefits of the ramp load-unload mechanism
[1].

[1]
[http://www.hgst.com/tech/techlib.nsf/techdocs/9076679E3EE400...](http://www.hgst.com/tech/techlib.nsf/techdocs/9076679E3EE4003E86256FAB005825FB)

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mirimir
What's the point of doing all of this in order to use desktop HDDs in servers?
Why not just use WD RE4s?

~~~
steveh73
They are cheaper, obviously

~~~
mirimir
Not really.

1 TB RE3: 48 USD[0]

1 TB RE4: 53 USD[1]

1 TB Green: 52 USD[2]

That's the cool thing about the RE line.

[0] [http://www.amazon.com/Western-Digital-Cache-Enterprise-
Drive...](http://www.amazon.com/Western-Digital-Cache-Enterprise-
Drive/dp/B001IEXU68)

[1] [http://www.amazon.com/RE4-Enterprise-Hard-Drive-
WD1003FBYX/d...](http://www.amazon.com/RE4-Enterprise-Hard-Drive-
WD1003FBYX/dp/B003SANWI6)

[2] [http://www.amazon.com/Green-1TB-Desktop-Hard-
Drive/dp/B006GD...](http://www.amazon.com/Green-1TB-Desktop-Hard-
Drive/dp/B006GDVREI)

