Le 19/11/2016 à 00:52, Brian :: a écrit : > This is like your mother telling not to cross the road when you were 4 > years of age but not telling you it was because you could be flattened > by a car :) > > Can you expand on your answer? If you are in a DC with AB power, > redundant UPS, dual feed from the electric company, onsite generators, > dual PSU servers, is it still a bad idea?
Yes it is. In such a datacenter where we have a Ceph cluster there was a complete shutdown because of a design error : the probes used by the solution responsible for starting and stopping the generators were installed before the breakers installed on the feeds. After a blackout where generators kicked in the breakers opened due to a surge when power was restored. The generators were stopped because power was restored, and the UPS systems failed 3 minutes later. Closing the breakers couldn't be done in time (you don't approach them without being heavily protected, putting on the suit to protect you needs more time than simply closing the breaker). There's no such thing as uninterruptible power supply. Best regards, Lionel _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com