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Facebook Putting Batteries On-Board Its Servers
1sockchuck writes "The data center of the future may have no central UPS units, and be filled with servers with on-board batteries. Facebook says it will adopt a new power distribution design that shifts the UPS and battery backup functions from the data center into the cabinet by adding a 12-volt battery to each server power supply, an approach pioneered by Google. Facebook says the move will slash its power bill and save millions in capital expenses on UPS systems and PDUs. Facebook acknowledged that these types of custom designs are limited to large companies, but called on server vendors and data center builders to adapt their offerings to make them available to smaller companies."
Since when is 12 Volts a measure of battery life? You still need to know how many Amp-Hours the battery can provide and the power usage of the server.
You could have a 100Amp-Hour 12 volt battery, or a 1Amp-Hour 12 volt battery...
What would the world be like if facebook went offline... I'm not sure I could continue living.
Only the State obtains its revenue by coercion. - Murray Rothbard
Facebook says the move will slash its power bill and save millions in capital expenses on UPS systems and PDUs.
And it'll move the complexity and unreliability to the server. The whole idea behind centralized UPS's (and by the way, you still need PDUs) is that you have reliability, serviceability, and economies of scale and efficiency. Now you have to monitor and service the batteries in thousands of pieces of equipment. And guess what happens when one of those batteries fails by getting cooked? Sulfuric acid all over the place (yes, even the "sealed" lead acid batteries can fail and leak) instead of the batteries being in, say, a battery room. God help us if they use lithium-ion, which would introduce us to a world of server fires and water damage, since a lot of datacenters are now dry-pipe to save costs. Nevermind that batteries and their associated electronics take up space, and that space has to come from somewhere.
So, now you have each server getting more expensive, more complex with both hardware and software (server now needs its own battery power management) heavier, bigger, featuring toxic materials, and now non-standard, non-commodity design which vendors will charge more for as they specialize the equipment.
I'm sure this all looks great on a powerpoint slide simplified into "if we put batteries in our servers, we can throw out our expensive UPS and save money!" This is just another hot/stupid trend; just because Google is doing it, doesn't make it brilliant. I stopped believing everything google was doing was a Best Practice around the same time gmail started going down for hours (and for some users, more than a day) at a time on a regular basis.
I tuned out of the article around the point where the guy from Facebook complains about cosmetic features interfering with airflow. Uh, guess what, bud? Dell's pretty front panel has been optional (saving you a few bucks sometimes) for years.
Please help metamoderate.
The wiring resistance is constant per meter (for a given cost) and increasing the voltage will reduce the amperage, while the power loss in the wiring is the multiplication of the amp times resistance, so, by increasing the voltage, the reduce the amp which in turn reduce the power loss in the transmission.
277 (V) corresponds to the line to neutral voltage of a 480 (V), 4 wire power distribution system. 480 (V) systems are fairly common in industrial settings in the United States. The major disadvantage of using 480 (V) to power a server, is you can't use a UPS. UPS on 480 (V) systems are rare and expensive, hence the reason why Facebook wants the batteries inside the server.
I'm pretty certain you really don't want to run servers from the 277 (V) line to neutral voltage of a 480 (V), 4 wire system (3 lives, one neutral). On a 4 wire system, you have 4 wires and you can lose any one of them. If you lose the neutral, your servers could be running of 480 (V) instead of 277 (V). They will be destroyed.
Losing the neutral is a relatively common failure in 3 phase systems, as many 3 phase systems are 3 phase, 3 wire with a fake neutral/ground connection that is often mistaken for a neutral. This central connection is purely to prevent the 3-wire system from drifting off of off ground, like when lightening strikes, which is common in a big high-voltage system. When operating a 10,000 (V) to 480 (V) step down transformer (the transformers inside the metal fenced enclosures), a small amount of electric slippage to occur between the windings. 1% of 10,000 (V) is 100 (V). Faults can also occur in big loads, like motors. A 10% ground fault on a 480 (V) 400 (A) motor, could be 200 (V) at 40 (A). These voltages/powers are nothing for a 480 (V) motor, but are enough to cause significant damage in a computer with a 1.2 (V) processor. This mismatch is why you should never trust the ground/neutral connection on a high-voltage supply line. It is for safety, not for powering computer equipment, electronic equipment, and electronic motor drives. After having replaced tens of thousands of dollars of electronic motor drives, my rule is: make the supply 480 (V) 4 wire, and all the loads 480 (V) 3 wire. A 3 wire load with no neutral can withstand problems with the neutral. A 4-wire load powering electronics line-to-neutral will not withstand neutral failures.
If you are going to use 480 (V), you really want to use 480 (V) 3 wire AC (3 live wires, no neutral). If any one power circuit is lost, nothing really bad happens. Also, power semiconductors are readily available for 480 (V), because all the industrial motor drives require them. As such, your power supply will be cheaper.
Could you dumb it down a shade?
If you have bigger pick up trucks, then you need less of them to carry a set amount of goods and so there is less traffic on a road.
IranAir Flight 655 never forget!