On Fri, 11 Oct 1996, Rob Liebschutz wrote:
I just spoke to their NOC and was told that a power switch that is supposed to be able to switch them between 3 different power utilities failed at 12:30 this morning (friday). They bought and installed 2 large diesel generators today and are hoping to be back up using the generators within 30 minutes.
Perhaps there is a lesson in redundancy here. Based on this account it would appear that although they had arranged for 3 power sources that there were two mistakes made. One was that switching between sources relied on a single piece of hardware thus negating the redundancy of 3 sources. The other was that they did not have alternate types of power source, i.e. they did not have generators on site but expected that 3 different utility power sources was adequate redundancy. Some NOC engineers (or perhaps NOC managers) aren't paranoid enough. Michael Dillon - ISP & Internet Consulting Memra Software Inc. - Fax: +1-604-546-3049 http://www.memra.com - E-mail: michael@memra.com