Working with a diagram on scratch paper, George illustrated how cloud developers kick the problem of a hardware component failure upstairs into the software running the cloud. The model dictates that the workload of a failed machine be moved elsewhere and picked up where it left off, or rerun. The failed server eventually gets repaired or replaced.
George quoted Dell's distinguished engineer and chief architect for cloud servers, Jimmy Pike, who has pointed out that "the resiliency is in the software, not the hardware," so Dell must adjust to that concept when designing cloud servers. Dell has had some practice. Microsoft's Azure cloud is to be announced in two weeks at its Professional Developers Conference in L.A., but Dell has been designing servers for Azure for three years.
So one of the first elements in cloud design is to strip out redundant parts, lowering the cost per server. A second element is to build in strong virtualization features, which include lots of memory, multi-core processors and, frequently, multiple host bus adapters for storage traffic or multiple network interface cards for network traffic, if the virtualization workload is likely to have lots of I/O.
There is no one design that is right for every cloud, George said, but at the same time clouds, including private clouds, will have many requirements in common and Dell must master the best practices of producing the right machine for a given cloud.
To help customers build private clouds, Dell's Data Center Solutions Group will offer templates of proven cloud servers and let customers browse among them. It will also cite best practices in the software stacks that go on those servers to become nodes in a cloud. Dell's DCS group already has experience in the field, George said.
"The way we look at it, cloud is not binary. It's not all or nothing in any one direction. It will be mix of IT (traditional IT infrastructure, with mainframes, Unix servers), a virtualized private cloud (based on x86 servers), and public cloud," he said. In other words, there will be collaboration between the data center of the future, which will include a private cloud, and the public cloud, such as EC2.
Some at the Cloud Computing Conference called such a federation the "hybrid cloud." George doesn't care what you call it. He just wants Dell to provide the basic building blocks that will run it.
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