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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."
This right after they announced they were going public. This will definitely boost their stock price.
I think facebook has some good merit, however I am an avid anti facebook poster boy when it comes to destroying
relationships. If you thought it was easy before to hook up online and cheat on your spouse, well imagine now!!!
Girlfriend: "Hey, i got over 5000 friends online, isn't it wonderful???"
Boyfriend: "ummm...why are they all pictures of young good looking dudes wearing no shirts....?"
Girlfriend: "well that's because you can put anything on there..."
Boyfriend: "how long have you know these so called friends?"
Girlfriend: "Well not long, most are people that invited me to be their friend"
Boyfriend: "Why is this guy keep writing on your wall how hot you are....I am not sure i really like this..."
Girlfriend: "You always make such a big deal about nothing..."
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
This is interesting to me in a couple of ways.
The idea is that it is cheaper to have just a battery instead of a UPS. A UPS will also have to have an inverter.
Okay I can see this but they why have it at the server level?
Remove the power supply from the server and put it at the rack level? Have a big redundant power supply for each rack and batteries for each rack?
Or why not use DC for the entire data center and put the battery at the Data Center level?
Seems to me that there may be more than one way to skin this cat and each have it's pluses. If you are using a large number of low load balanced servers where having any one go down isn't a disaster then putting the battery on the server would give you a good trade off. You are probably more likely to have a single server to fail than a more centralized system would but the odds of taking down the system would be tiny.
I would love to see a study of the benefits of each type of system with the trade offs.
See my blog http://ilovecookes.blogspot.com/ for light hearted technical information.
Distributed!
Centralized!
Distributed!
Centralized!
Distr...
ad infinitum
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.
I used to work at a company that decided to install large, monolithic UPS systems after the power company hit them with a spike that took the entire system down for over a half hour. As they're a broadcasting company, they (rightly) felt that feeding their network affiliates nothing was not a good idea.
As a result, they have these UPS "rooms" that hum like the dickens when you're passing them in the hall, all with batteries that will need to be replaced regularly (just like the Google server battery systems, so it's the same problem no matter what). Reason for the hum?
The hum is caused by these giant transformers that step the power from DC to AC and create 110 volts of AC current at whatever amperage is required for normal devices. But there is a lot of wasted energy in doing that.
Computers and servers all run off of DC power. They plug into AC power and then run that AC through a "power supply" that converts that to DC that the computer can use. That takes power, but power is plentiful when it comes from the power company and you pay your bill on time. But when you take the power from the power company, then change it to DC to charge batteries and then take power from those batteries to change it to AC to power normal wall outlets only to take that through a server's power supply to change it to DC again for the computer to use it, you're looking at lots of wasted energy in just changing from AC to DC, back and then back again, as well as changing to the kind of voltage and amperage needed to run the microprocessor, power the memory and power the drive arrays.
So this is all about lowering consumption. And if you lower consumption, you lower your electricity costs.
The hobbyist magazines were all aflutter some years ago about using photovoltaic (solar) energy to power a house. But what everyone had to do (early on) was to change their appliances (or order special ones) to run on DC -- not because you couldn't make AC current from the DC output of the photovoltaic systems but because it took a lot of energy to do that and these hobbyists were all about trying to save so much energy that they could take themselves off the grid.
Here, on a large scale, you see the same idea. It's just more efficient to do this. And one of the big arguments in the early years of electrification was between DC power distribution (Thomas Edison) and AC power distribution (George Westinghouse and Nikola Tesla). We may wind up fighting these battles again in the near future.
Gods don't kill people, people with gods kill people.
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!
Those Pentium IIs are what gives me something to do... so many break/fix calls between them and the same company's over-complicated network.
My point was just that you can't assume everyone has the same refresh cycle, just like you shouldn't assume that all servers are in a datacentre, or that racks are only in a datacentre, or that all servers are on racks, etc. There's a lot of variety out there.