When we talk about server virtualization, we often mention the resources behind the technology, such as the memory, CPU, and disk. We do so because at least one of these resources will ultimately become the bottleneck somewhere down the road on our path to consolidation. But what about the network? Remember the network -- that thing that everyone used to point the finger at and assign blame to when something went wrong in the data center?
The network is another virtualization resource, but one that doesn't get nearly as much attention as the other three.
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For the longest time, virtual networking wasn't necessarily top of mind for virtualization administrators. In the dark ages of virtualization, they only had to deal with a simple virtualized network adapter. At the time, providing a virtual NIC seemed to be quite enough for basic virtualization deployments. Soon after, the platform vendors threw a rather simple proprietary switch into the mix but with very little sizzle and not much of a cool factor to it. For a while, that was pretty much the status quo and, for the most part, acceptable.
By 2009, we had reached the age of enlightenment in the virtual world. Server virtualization platforms had matured, and virtualization administrators began architecting and deploying more complicated solutions and environments. Because of that, more virtual networking control became required. This was also the period when Cisco got into the game with the company's first entry into the virtual switch market, the Nexus 1000V. It was a virtual machine access switch, and an intelligent software switch implementation for VMware vSphere environments running the Cisco NX-OS Software operating system.
The interesting thing here was that if your physical data center was operating on Cisco gear, the Nexus 1000V provided a consistent networking feature set and provisioning process all the way from the virtual machine access layer to the core of the data center network infrastructure. This was a big deal, and it brought the sexy back to virtual networking and helped put the resource back on the virtual map.
But Cisco wouldn't be alone on this virtual switch quest for very long. The company had to know that something as useful as the Nexus 1000V wouldn't be without competition for any extended period of time -- it wasn't.
Shortly on the heels of the 1000V release, a new project was launched but with little fanfare; it was called the Open vSwitch Project. At the time of its launch, there was very little insight into exactly who was behind the project. Although there still aren't any company names blasted on the project's Website, it looks as though there may be involvement by Nicira (the virtualized networking startup with financial backing from ex-VMware CEO Diane Greene) and possibly Citrix.
The Open vSwitch is described as a multilayer virtual switch licensed under the open source Apache 2 license. It is designed to support distribution across multiple physical servers similar to VMware's distributed vSwitch or Cisco's Nexus 1000V.