``Sticktion'' and Seagate/Imprimis/CDC Wren drives...

[Brad L. Knowles]

After a number reciving a number of requests to post further information
on ``sticktion'' and Seagate/Imprimis/Control Data Corporation (CDC)
drives, I have compiled the following.  It is being cross-posted to
Sun-Managers and Sun-Spots, in hopes that it will find it's way to some
interested folks that are on one, but not the other.

I would first recommend that you seriously re-consider slapping the
drives.  I have had private responses from people who have said (in
effect) "Yah, I slapped (or kicked!) the drive pretty hard, it still
didn't work and had to be sent back to the manufacturer."  I think I can
tell you what they found inside the drive afterwards -- Head material
splattered all over the inside of the drive, the heads ripped off the
actuator arms, perhaps even scratches and gouges all over the media
because the actuator arms got bent and came into physical contact with the
media.  All in all, if you ever saw the insides of a drive that got
slapped too hard, you might loose your cookies -- it's *not* a pretty
sight!

It is pretty easy to detect the drive having been slapped too hard, all
you have to do is look for external indications of having been dropped, or
whatever (looking for bent sheet metal, etc...).  If you don't find any,
then you can be pretty well assured that the drive was slapped
intentionally, as opposed to being accidentally dropped.  This is a very
good reason for voiding the waranty of the drive in question.

What I recommend instead is that you follow these instructions (at your
own risk, of course):

Parts Needed: Hair dryer or space heater, accurate and fairly small
  thermometer, tool(s) to open the OEM drive enclosure (shoebox) that the
  Seagate/Imprimis/CDC drive is in.

1.  Turn off the power to your shoebox.
2.  Disconnect all power and data cables to the drive.
3.  Remove the drive from the shoebox.
4.  Reconnect all data and power cables to the drive.
5.  Start a program running that constantly tries to access the drive.
    Anything simple will do, so long as it loops forever (until stopped by a
    signal that you intentionally give it).
6.  Place the thermometer on top of the drive.
7.  Start up the hair dryer or space heater at the lowest setting.  Make
    sure that the drive is heated as evenly as possible.
8.  Slowly increase the setting of the heater, watching the temperature as
    you go.  Make sure the temperature does not exceed 110 degrees Fahrenheit.
9.  Once the drive becomes accessible, keep the temperature fairly constant
    for at least five to ten more minutes.
10. Slowly decrease the setting of the heater, thus slowly decreasing the
    ambient temperature near the drive (watching the thermometer as you go).
11. Stop the program that has been accessing the drive.
12. Power back down, putting the drive back the way you found it.

Remember, Seagate/Imprimis/CDC Wren drives do not like cold temperatures
-- If you feel completely comfortable in the room that they are in, while
you are wearing shorts and short-sleeve shirts, then the drives will also
be comfortable.  If the computer room is kept at 50-60 degrees Fahrenheit,
then you are almost guaranteed to have problems, perhaps chronic ones.

Also, the above is primarily intended for the Wren III - VI drives.  The
Wren VII is a different kind of beast, and may or may not be amenable to
this kind of treatment.  The above may actually be harmful to drives from
other manufacturers, or other models from the same manufacturer(s).  I
seem to remember that the Wren IV and Wren V models were most susceptible
to sticktion, but that may be my memory playing tricks on me.

Finally, if my procedures don't work for you, then I would recommend that
you send the drive back to the manufacturer -- they can send it back to
Seagate, and have the folks in the clean room fix your problem for you,
without causing any damage to the drive or data on the drive.

I take no responsibility for anything you may do while trying to fix your
sticktion problems, whether you are using my procedures or not -- the
above should work fine for most folks, but you use whatever procedures you
choose, entirely at your own risk.

Please respond via e-mail.  I will summarize and re-post, if appropriate.
 ________________________________________________________________________ 
| Brad Knowles                 | Internet: blknowle at frodo.jdssc.dca.mil  |
| System Administrator         |       or: blknowle at wis-cms.dca.mil      |
| DCA/JDSSC/JNSL               | Ph: (703) 693-5849  Fax: (703) 693-7329 |
| The Pentagon, Room BE685     |_________________________________________|
| Washington, D.C.  20301-7010 | my opinions != DCA's opinions or policy |
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