From mboxrd@z Thu Jan 1 00:00:00 1970 From: clemc at ccc.com (Clem Cole) Date: Wed, 3 Jul 2019 14:42:46 -0400 Subject: [COFF] Disk Technology was [Simh] Which PDP-11 to choose In-Reply-To: References: <6e8cdcbf-7183-1082-0437-403a6f3b2994@gmail.com> <25855953-9505-481C-A0E2-1AAD53B7BEC5@ccc.com> <28FA3347-B880-400A-B606-1240C83FA867@ccc.com> <005401d5300f$74588a60$5d099f20$@twsoft.co.uk> <20190701141124.GP1912@mcvoy.com> <00c901d530db$cf7b40f0$6e71c2d0$@twsoft.co.uk> Message-ID: 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 [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 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 > 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 >> >> by DA Patterson - ‎1989 - ‎Cited by 324 >> - >> ‎Related articles >> >> 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 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 >>> 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 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 >>>>> *Cc:* Clem Cole ; Patrick Finnegan < >>>>> pat at computer-refuge.org>; COFF ; 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 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. >>>>> _______________________________________________ >>>>> COFF mailing list >>>>> COFF at minnie.tuhs.org >>>>> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff >>>>> >>>>> >>>>> >>>>> Virus-free. >>>>> www.avast.com >>>>> >>>>> <#m_-5891018402996361374_m_2142356106908993712_m_1751084755802734138_m_-5102461650516400670_m_-7814325232288781299_DAB4FAD8-2DD7-40BB-A1B8-4E2AA1F9FDF2> >>>>> >>>> _______________________________________________ >>>> COFF mailing list >>>> COFF at minnie.tuhs.org >>>> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff >>>> >>> _______________________________________________ >> COFF mailing list >> COFF at minnie.tuhs.org >> https://minnie.tuhs.org/cgi-bin/mailman/listinfo/coff >> > -------------- next part -------------- An HTML attachment was scrubbed... URL: