[ntp:hackers] Headlights in the tunnel

Brad Knowles brad.knowles at skynet.be
Sun Sep 7 07:00:10 PDT 2003


At 2:13 AM +0000 2003/09/07, David L. Mills wrote:

>  Interesting idea. One of the two fried disks is still under warranty, so
>  we sent it back. Interesting thing is whether Sun does just the same as
>  you discribed - transplant the controller. If that works, the disk we
>  get back may actually still have the goodies.

	I wouldn't count on it.  My experience with vendors tells me that 
they will probably just pick a drive that is on-hand and which is 
considered to be at least as good as the failed drive (i.e., 
comparable capacity, rotational speed, etc...) and that's what 
they'll send to you.

	If you had sent the drive to DriveSavers (or some equivalent 
drive recovery company), they would have made every possible effort 
to get the data off the drive, which they would return to you on tape 
or DVD, or whatever media you specified.  Of course, that's extremely 
expensive.

>  Once upon a time I worked in a huge machine room with multiple disk
>  farms where each disk farm had ten platters some 12-inches in diameter.

	I didn't work on the Honeywell mainframe floor when my office was 
in the basement of the Pentagon, but I had a friend who did and I did 
tour through a few times.  I remember seeing refrigerator-size drive 
units that had removable disk packs with five or ten 12" platters.  I 
also remember that they used to take old platters and turn them into 
"going away" plaques for people who had worked there.  I think I 
still have one of the very last 12" platters that were rescued before 
the last of those drives were de-commissioned.

>  Firing up an eight-disk farm the size of a couple of Volkswagens gave
>  new meaning to the term rotating inertia. Well, one day something evil
>  happend in the controller and scrambled all eight disk arms turning them
>  into oxide plows. There was a loud screech and all eight transparent
>  disk peepholes turned oxide brown.

	I saw some extremely ugly things during my three-month internship 
with Imprimis Technologies (before they got bought by Seagate).  I 
was working with the Manufacturing Engineers, doing programming for 
statistical quality control.  I never did manage to take that clean 
room tour, but I did get to see serial #1 of the Wren VII line, which 
was the first 5.25" drive to have 1GB of storage.  ISTR it was also 
quite a bit faster than other drives at the time.

	If you ever want to see some seriously nasty stuff, take a look 
at a failed drive under a microscope, where the lubricating grease in 
the spindle liquified due to excessive heating and spread all over 
the surface of the media, then congealed in place as the drive cooled 
down after being turned off.  Then, the heads became stuck to the 
platters ("stiction") because of the congealed grease, and were 
promptly ripped off the armatures when the drive was powered up again.

>  The fiberchannel disks in mort are a touch imbalanced and each emits a
>  166-Hz hum which beats with each other with about ten-second period.

	That would drive me seriously nuts.  Even if I had a separate 
machine room which was acoustically isolated from the rest of the 
house, I don't think I could ever go in there again.

-- 
Brad Knowles, <brad.knowles at skynet.be>

"They that can give up essential liberty to obtain a little temporary
safety deserve neither liberty nor safety."
     -Benjamin Franklin, Historical Review of Pennsylvania.

GCS/IT d+(-) s:+(++)>: a C++(+++)$ UMBSHI++++$ P+>++ L+ !E-(---) W+++(--) N+
!w--- O- M++ V PS++(+++) PE- Y+(++) PGP>+++ t+(+++) 5++(+++) X++(+++) R+(+++)
tv+(+++) b+(++++) DI+(++++) D+(++) G+(++++) e++>++++ h--- r---(+++)* z(+++)



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