Nothing as drastic as the alleged FastRand, but I can vouch for 3330 and 3330-equivalent drives dancing. My boss told me to write a program that started at the middle of the pack and then did seeks in and out to the first untouched cylinder until it had hit every cylinder. I told him that the timings from the test would have no relevance to performance in the wild, but he insisted that I write it anyway.
-- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> on behalf of William Donzelli <wdonze...@gmail.com> Sent: Tuesday, July 23, 2019 12:29 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: DASD nostalgia > OK, you are referring to Seymours alleged drum tearing loose on a navy ship. > > Mea Culpa. I read this as you disputing that the Navy installed FirstRand 1 > on its ships. Just a misunderstand, pretty much. > There are a references to this model being a dancing behemoth, and that the > counter-rotating drum resolved this. Yes, I can see that one of these not bolted to the floor - any floor - would start walking around on its own. It would not even need help (like disk drive races, as done university students). > There are a few, unsubstantiated references to failures sending the drum > through a wall(s). They make for good stories. -- Will ---------------------------------------------------------------------- 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
