Virtualization requires an entirely new way of thinking about networking, said Gartner analyst Mark Fabbi. "Virtualization changes everything, how we look at server I/O, how we deal with branch offices and disaster recovery."
Gartner reckons in virtualized environments there is "25 times more bandwidth coming from the same physical footprint," and the server I/O needs to be moved from 1G to 10Gbps, Fabbi said. "40G output is on the horizon in the high-performance blades," he noted. "The idea of 40G I/O off the servers isn't far-fetched."
One of the main drivers for all this "clearly is VMware," he said, noting that virtualization's "voracious appetite" is seen in VMware capabilities such as Vmotion. "In a virtual environment, things are shifting around." The rippling effect of all of this is that the top of rack switch will need to be pushed from 10G to 40G, using technologies like Infiniband. There may be savings in consolidating I/O, but "the challenge is in the rack," he said.
Virtualization is prompting a shift from a classic three-tier architecture to two, Fabbi said, saying the future network architecture for all this is more focused on Layer 2 than Layer 3. The newer fabric-based architectures from HP, the VCE Cisco alliance with VMware and EMC, and IBM — in addition to any decision to "roll your own" — should be evaluated, he said.
But data centers may still have "multiple domains," he said, for instance, "A VMware domain and a Hyper-V domain. In large organizations, you may have multiple domains. We don't think it will be totally homogeneous."
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