[COFF] Disk Technology was [Simh] Which PDP-11 to choose

Thu Jul 4 04:42:46 AEST 2019

BTW:   for those not around in the 1970's Dave's reference to the 'Pinto'
here it is:
Ford Pinto issues
THE *FORD PINTO* CASE: The cases involving the explosion of *Ford Pinto's* due
to a defective fuel system design led to the debate of many *issues*, most
centering around the use by *Ford* of a cost-benefit analysis and the
ethics surrounding its decision not to upgrade the fuel system based on
this analysis.
THE FORD PINTO CASE:
https://users.wfu.edu/palmitar/Law&Valuation/Papers/1999/Leggett-pinto.html
<https://users.wfu.edu/palmitar/Law&Valuation/Papers/1999/Leggett-pinto.html>

[When I was in college, another student at CMU painted a large Bull's Eye
on the back of him Pinto]

On Wed, Jul 3, 2019 at 2:38 PM Clem Cole <clemc at ccc.com> wrote:

> John - not much there:
>
> Introduction to redundant arrays of inexpensive disks (RAID)
> From Page 112, Bottom of 1st column continued to the top of second the
> text is:
>
> While the magnetic disk industry has made little progress in improving
> speed of disks, it has significantly reduced the size of disks. The
> personal computer industry has created a market for 5.25 and 3.5 inch
> drives, reducing the cost per disk system as well as the traditional
> lowering of cost per megabyte. Table I below compares the top-of-the-line
> IBM 3380 model AK4 mainframe disk, Fujitsu M2361A "Super Eagle"
> minicomputer disk, Impress/CDC Wren-IV workstation disk, and the Conner Peripherals
> CP 3100 personal computer disk.
>
> From Page 116, Second column the text is;
>
> One problem that several magnetic disk manufacturers have mentioned is
> what we would call the "Pinto Effect;" a mistake is made in manufacturing
> process that is so disastrous that the disk manufacturer will recall all
> affected disks and replace them. The common theme is that the mistake is
> uncovered after the disks have been in the field for several months and the
> disks all fail within a short time of one another. One example was a
> manufacturer who glued together the two halves of an head-disk assembly,
> with this glue dissolving after the disks had been in the field for 18
> months. Another example was that a new bateriacide used in an air filter
> interacted with the disk surface so that many failures occurred six months
> later. A common cause of the Pinto Effect is that a supplier will change
> some component as a cost cutting measure without notifying the disk
> manufacturer, and disastrous consequences occur due to unforeseen
> interactions.
>
> Although we desperately need real data on disk failures, we are performing
> studies of using models to estimate the impact of the Pinto Effect on RAID
> reliability.
>
> On Wed, Jul 3, 2019 at 2:02 PM John P. Linderman <jpl.jpl at gmail.com>
> wrote:
>
>> The best I could find googling *fujitsu super eagle "glue"* was
>>
>> Introduction to redundant arrays of inexpensive disks ... - IEEE Xplore
>> https://ieeexplore.ieee.org/iel2/231/7454/00301912.pdf
>> <https://ieeexplore.ieee.org/iel2/231/7454/00301912.pdf>
>> by DA Patterson - ‎1989 - ‎Cited by 324
>> <https://scholar.google.com/scholar?biw=1544&bih=764&um=1&ie=UTF-8&lr&cites=11507519054000724161> -
>> ‎Related articles
>> <https://scholar.google.com/scholar?biw=1544&bih=764&um=1&ie=UTF-8&lr&q=related:wZjAM5zrsp8u3M:scholar.google.com/>
>> computers, the Fujitsu M2361A "Super Eagle" disk for minicomputers,
>> ..... assembly, with this gluedissolving after the disks had been in the
>> field for 18 months.
>>
>> Tantalizing, but I couldn't dig further, perhaps because I'm not a member
>> of IEEE.
>>
>> On Tue, Jul 2, 2019 at 5:34 PM Rico Pajarola <rp at servium.ch> wrote:
>>
>>> if you still have that story, I'd love to hear it. A quick search didn't
>>> turn up anything except that Super Eagles is a Nigerian football team.
>>>
>>>
>>> On Tue, Jul 2, 2019 at 12:59 PM John P. Linderman <jpl.jpl at gmail.com>
>>> wrote:
>>>
>>>> I don't have authoritative info on the cause, I'm just repeating what I
>>>> heard. A highly viscous substance like glue would explain why it took so
>>>> long to fail. In any event, it was nasty. Worked perfectly long enough to
>>>> build confidence, then failed spectacularly. It was widespread. I entered a
>>>> "Sysadmin Horror Story" contest at a USENIX (San Diego?), and won with a
>>>> "short story" entry: *Supereagles*. I still have the shark's tooth
>>>> trophy.
>>>>
>>>> On Tue, Jul 2, 2019 at 9:41 AM Tim Wilkinson <tjw at twsoft.co.uk> wrote:
>>>>
>>>>>
>>>>>
>>>>> Interesting that it was the platter bonding. The explanation SI gave
>>>>> us (They sold us the super Eagles along with their controller) was that it
>>>>> was a lubricant. So I had assumed a bearing seal fail.
>>>>>
>>>>>
>>>>>
>>>>> Anyway after about 4 swap outs and a lot of lifting they lasted a
>>>>> further 15 years until we knocked down the office with the original 750 and
>>>>> its big brother an 8810 still in the computer room as all the resellers
>>>>> wanted certificates of continuing maintenance that would have cost more
>>>>> than they were willing to pay for those vaxs.
>>>>>
>>>>>
>>>>>
>>>>> *From:* John P. Linderman [mailto:jpl.jpl at gmail.com]
>>>>> *Sent:* 02 July 2019 12:47
>>>>> *To:* Larry McVoy <lm at mcvoy.com>
>>>>> *Cc:* Clem Cole <clemc at ccc.com>; Patrick Finnegan <
>>>>> pat at computer-refuge.org>; COFF <coff at minnie.tuhs.org>; Tim Wilkinson <
>>>>> tjw at twsoft.co.uk>
>>>>> *Subject:* Re: [COFF] Disk Technology was [Simh] Which PDP-11 to
>>>>> choose
>>>>>
>>>>>
>>>>>
>>>>> There were eagles, and then there were super-eagles. Our experience
>>>>> with eagles was great, and we were eager to try the (larger) super-eagles.
>>>>> We soaked them for a month or so, then put them into production use.
>>>>> Whereupon, they started dropping like flies. It turns out the glue they
>>>>> used to attach the platters to the spindle slowly crept out over time,
>>>>> eventually coming to grief with a read/write head. This experience was
>>>>> wide-spread, and seriously damaged Fujitsu's reputation.
>>>>>
>>>>>
>>>>>
>>>>> On Mon, Jul 1, 2019 at 10:11 AM Larry McVoy <lm at mcvoy.com> wrote:
>>>>>
>>>>> On Mon, Jul 01, 2019 at 09:49:42AM -0400, Clem Cole wrote:
>>>>> >  An Eagle or Eagle-II was a whole lot lighter (and physically
>>>>> smaller) than
>>>>> > an RP06 or RP07 (or an RM series drive for that matter). It is
>>>>> interesting
>>>>> > to hear you had problems with the Eagles.   They were generally
>>>>> considered
>>>>> > the best/most reliable of the day.   The SI controller on the Vax
>>>>> was less
>>>>> > so, although many of us in the UNIX community used them.
>>>>>
>>>>> We ran Eagles on the Masscomps we had at Geophysics.  Nothing but good
>>>>> things to say about those drives.
>>>>> _______________________________________________
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>>>>>
>>>>>
>>>>>
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>>>>>
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