At least your data center isn’t known for it’s armed robberies:

http://www.datacenterknowledge.com/archives/2007/11/04/armed-robbery-at-chicago-data-center/

Gotta give the thugs credit for style worthy of a Hollywood director…cut hole in wall, when night manager investigates hit him with the taser and tie him up.

And that was their fourth break in.

At least your data center isn’t known for it’s armed robberies:

http://www.datacenterknowledge.com/archives/2007/11/04/armed-robbery-at-chicago-data-center/

Gotta give the thugs credit for style worthy of a Hollywood director…cut hole in wall, when night manager investigates hit him with the taser and tie him up.

And that was their fourth break in.

Although I heard of it before, I had never seen it in person. Makes uninterruptible power supply a snap — everything is fed by a bank of fairly standard batteries that are kept charged by the power grid.

The power supplies for the data center are usually reading in the mid 50s for voltage and a smidge over 500amps on their meters when I walk by.

The commercial off-the-shelf servers we run still are traditional 110VAC, due to the extra expense of buying 48VDC power units in each server.

I reckon like MANY things on the internet and computing, 110VAC is prevelant simply because it got in the door first and the cost of rebuilding the infrastructure to use DC today is too great. Email, IPv4 (the IP addresses we’re familiar with), and the current Domain Name Server systems are all the same — no one in their right mind would chose from scratch today what we actually use. But no one wants to encounter the pain and cost today of fixing it.

Google splits the difference in the servers they custom build. They use 110VAC to each server, but the AC charges an internal 12VDC battery. Unlike most motherboards that use multiple voltages (usually both 5V & 12VDC), the Google boards use just 12V. So Google has no central uniterruptible power supplies for their data centers — each server has it’s own small battery to keep it running through a momentary power glitch, or provide time to shutdown cleanly if it’s an extended outage.

Although I heard of it before, I had never seen it in person. Makes uninterruptible power supply a snap — everything is fed by a bank of fairly standard batteries that are kept charged by the power grid.

The power supplies for the data center are usually reading in the mid 50s for voltage and a smidge over 500amps on their meters when I walk by.

The commercial off-the-shelf servers we run still are traditional 110VAC, due to the extra expense of buying 48VDC power units in each server.

I reckon like MANY things on the internet and computing, 110VAC is prevelant simply because it got in the door first and the cost of rebuilding the infrastructure to use DC today is too great. Email, IPv4 (the IP addresses we’re familiar with), and the current Domain Name Server systems are all the same — no one in their right mind would chose from scratch today what we actually use. But no one wants to encounter the pain and cost today of fixing it.

Google splits the difference in the servers they custom build. They use 110VAC to each server, but the AC charges an internal 12VDC battery. Unlike most motherboards that use multiple voltages (usually both 5V & 12VDC), the Google boards use just 12V. So Google has no central uniterruptible power supplies for their data centers — each server has it’s own small battery to keep it running through a momentary power glitch, or provide time to shutdown cleanly if it’s an extended outage.