They do run Linux. And they built their own distributed file system to handle the thousands of nodes/large file cache they deal with.
I'll see if I can dig up the file system article... Here it is: http://labs.google.com/papers/gfs-sosp2003.pdf -sc -----Original Message----- From: Ben Scott [mailto:[email protected]] Sent: Thursday, April 02, 2009 7:12 PM To: NT System Admin Issues Subject: Re: OTish: Googles Servers On Thu, Apr 2, 2009 at 6:16 PM, Peter van Houten <[email protected]> wrote: > . The power supply claims an input voltage of "200-240vac". When did you > folks on the other side of the pond raise your voltage? I seem to recall that Google was experimenting with plant DC distribution to commodity PC hardware, and they had discovered that if you feed a DC battery into the input of a 240 VAC power supply, it worked. I don't recall what the battery voltage was. This also might be something completely different; I'm just speculating. The advantage of an all DC power system is that you don't waste money converting from DC to AC and back again, like you do with a conventional UPS. You just have a giant battery plant as the primary power source. AC is used just to keep the battery charged. If AC fails, there's no UPS switch-over; the batteries just stop charging for a little while. The telco's figured this out decades ago; all their equipment runs on 48 VDC. > . Lack of display and audio sockets, even though the PCB is designed for > these connectors. I'm guessing their "custom" motherboard is really semi-custom, i.e., based on a reference design and tweaked as needed. Even just leaving off an IC can save significant money when you buy motherboards by the thousands. > . Keyboard, mouse, USB, LAN and 9 pin serial ports. Serial port??? As someone else said, that's almost certainly for the system console. Linux ain't Windows; it doesn't need a graphics card. Again, if you're doing tens of thousands of systems, the cost savings can be substantial. Not only are serial console boxes cheaper than KVMs, they save by not buying graphics ICs and not powering graphics ICs. Plus serial can go tens of feet without signal degradation, unlike VGA and PS/2. No need to put a KVM in every server rack. > I've read that Google use Linux; any guesses how much RAM in those 8 > sticks? If it is circa 2007, probably 4GB? It prolly depends on whether Google's software is bound by I/O, CPU, RAM, or whatever. They've got the money and the situation where if, e.g., 8 GB would make more sense, it would pay off to do that. Linux doesn't have all the memory limitations that Windows does, so that wouldn't be an issue. Even 32-bit Linux can handle more than 4 GB of RAM with PAE. But I'd guess Google is running 64-bit Linux, which has been around since at least 1996, and was running on AMD64 from day one. Google's in a situation where, even if they weren't mortal enemies of Microsoft, they'd prolly go with Linux or another free Unix. Hundreds of thousands of nodes, so economies of scale pay off in the millions of dollars. All custom software, so no need to worry about running apps that only run on 'doze. So by leaving out hardware that Windows needs but *nix doesn't, they save on both equipment and operating costs. They can spend man-years tuning and modifying the OS for the absolute best performance for their application, well beyond anything you can do with Windows. Plus all the license fees they save. Of course, that's a somewhat unique situation, but I don't doubt that it worries Microsoft anyway. There's lots of big companies with big IT operations who might get ideas Microsoft wouldn't like. -- Ben ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~ ~ Finally, powerful endpoint security that ISN'T a resource hog! ~ ~ <http://www.sunbeltsoftware.com/Business/VIPRE-Enterprise/> ~
