You are currently browsing the monthly archive for December 2008.
Three undersea cables cut: traffic disturbed between Europe and Asia: Theses cables are (were) owned by French telco France Telecom, interesting because it is not the fist time in this region for 2008 and among all conspiracy theories, ship’s anchors or foreign intelligence taps are reported guilty. Cost for each reparation is estimated 60 000$ (fine paid by a Korean boat). Important point : all Asia Internet access is impacted.
Building a Green Windows Home Server, Build a Green 400$ Windows Home Server : Good initiatives but the result should be compared to NASes: they have maybe less functionnalities but less power usage for a two disks setup (if I take Synology for comparison – some goes below 32.4 watts full load versus 37 watts idle for the setup pictured). Worth reading anyhow!
Following previous article, I found this interesting piece from Datacenter Knowledge and so decided to vampire it and dig more into related contents.
First, this nice schema well introduces PUE:
As more and more PUE adopters are releasing into the wild PUE values (improbably low numbers, lower than competitor if possible), a controversy is starting on the reality and seriousness of theses figures. PUE is simple to calculate with only basic guidance, evolving to an industry standard without the discussions and collaboration typical to norms. Fast adoption could be an evidence that it is a too easy game:
- approximations (measurement, weighted average) : It is complicate to measure everything in a datacenter, like it should be for PUE. Old infrastructure are not that flexible and when it is not designed from begining, it can’t evolve. If your datacenter is in an office building for exemple, it could be that generator, power conversion, UPS and cooling are shared amongst many usages and users. Google for exemple is not taking into accounts small values so small datacenters. The sampling method is also important in any measurements and as coolings is highly linked to seasons, should not be discarded in reports. PUE varies! See illustration from Microsoft who has a hidden modesty showing it.
- use of products’ manufacturer technical value instead of real one. It can’t believe they went to every server, every PSU to measure it. They just make maths from the spec sheet. I do. I wish I could measure it, some servers give that information but it is just easier to get to the point. And more scalable.
- restricted scope : PUE is often calculated for modern, self-owned facilities ? How about the one you lease, the racks provided by your telco to host internet services, etc. PUE is used then as a justification for investment in new and shiny datacenters, not as a metric for IT efficiency.
Again, PUE is not a norm, standard or certification, it is just a metric.
It remains the way to go of course, incorporated in a global effort, involving desktops in the scope…
It is always good to pay attention to this.
Facts and links after the jump.
Green IT links round up, classified by category (read entire post to get content):
- Information
- Blog
- Metrics certifactions
- Manufacturers
More to come…
