What kind of disk dies silently? When our fixed-head disk crashed after multiple power failures it screamed like all the banshees in Hell, and the was no doubt about what was happening. IBM said they could have it back up in two weeks, and I thought they were blowing smokes. They flew in a special team that did nothing but repair 2305 drives
Part of the procedure after repair is to hook up measurement equipment and spin for 24 hours, install the heads and spin for another 24 hours. If the instrument detects anything out of balance you fix it and start the test from the beginning, not from where you left off. We had a power while they were testing, and they still turned over the working drive within the 2 weeks they had promised. I don't impress easily, but they impressed me. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of Tom Brennan <t...@tombrennansoftware.com> Sent: Saturday, April 13, 2019 1:27 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Incoming | Computerworld SHARK TANK Interesting story! The only time I've actually seen a head crash was on an old 3330 where I had just popped in a RES pack. I walked over to the hardware console to IPL - the old 3270 where you had to type L1/A2 or whatever those commands were. The hardware console told me I had an I/O error, and there was a red light on the device. I pushed the button to open the 3330 drawer and there were bits of disk head all over the inside. On 4/13/2019 9:16 AM, Gabe Goldberg wrote: > Many years ago I had friends in old DEC building in Maynard, MA. They > had story of periodic head crashes on monster disk drives with > vertically spinning platters. They realized cause: trucks backing into > loading dock hitting and shaking the building -- since platters were > oriented perpendicular to truck motion. Solution: turn drives 90 degrees > to align platters with truck motion. At worst, I/O errors but no head > crashes (I guess heads flew much higher than on today's devices). I'll > ask veterans I know of that time/place to confirm... > > ITschak Mugzach<imugz...@gmail.com> said: > > That reminds me another story. ten years ago a client of us installed a new > hitachi disk array. The technician installed and configured the array, but > for some reasons, it was not immediately used by the client. few days > later, the client tried to connect to the array and it was down. it was > repeatedly don everyday afterwards. investigation showed that the the > people who cleans the computer room unplugged the power for the vacuum > cleaner... The array was using a standard power plug. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > > ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
