On Fri, 24 Apr 2020, Ethan O'Toole via vcf-midatlantic wrote:
I used to work for a large music streaming provider and we had thousands and thousand of servers. The data center would put out a notice that they're going to do UPS maintenance or Switchgear maintenance... and usually that night we would have maybe up to 20 servers have issues. Hard hang or maybe a reboot. Meanwhile everything looked okay.
At one point, I had a production server in the data center, an IBM RS6000 with redundant power supplies (2). The techs were moving systems to a different power bus and unplugged one of the supplies: my system promptly shut down. It turned out that my system required THREE power supplies before redundancy was in effect. Oops. Mike Loewen mloewen@cpumagic.scol.pa.us Old Technology http://q7.neurotica.com/Oldtech/