Originally Posted by
fergusd
Anybody with the barest minimum of knowledge would deploy only server chassis fitted with two power supplies, each fed from diverse electrical feeds in the data center, backed up using different UPS's each connected to different diesel backup generators. Professional kit deployed by professionals can always be deployed with multiple power supplies. Short of a catastrophic event at the data center (bomb/flood/plane crash) you don't lose power on all power feeds.
According to the Yahoo video recently posted here this may not be a good strategy. It’s introducing so much complexity that it may reduce reliability, especially if you consider the extra possibilities of fire and human error.
In one centre where we tried to reliability model the power system it was so complex we could not mathematically model it. Intuitively it had so many backups it seemed to be bullet proof, but if it can’t be modelled how can we be really sure?