Simplify VMware vSphere* 4 Networking with Intel Ethernet 10 Gigabit Server Adapters

The Foundation of Virtualization
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sporadic trac spikes from that port group, additional server adapters
must be added (assuming additional PCI* slots are available). Additionally,
the bandwidth allocated in the example cannot be used by any other
trac; it simply goes to waste.
On the other hand, handling the port group with bandwidth from a
shared 10GbE server adapter allows additional bandwidth to be allocated
for trac spikes more seamlessly. Furthermore, multiple port groups
can share the bandwidth headroom provided by the server adapter. The
resource can be automatically and dynamically reallocated as various
port groups are accessed by their associated VMs. Dedicated band-
width is not needed for any one port group as long as the host network
connection never reaches saturation. This method is very similar to how
VMware shares processor resources, allowing VMs to burst processor
utilization as needed due to the likelihood that many VMs won’t burst at
the same time.
The Intel Networking Test lab confirms the viability of replacing multiple
GbE ports with a pair of 10GbE ports in the configuration mentioned in
this paper. A number of VMs were installed on each of two hosts, and
the process of migrating all of the VMs on one host to the other and
back again was timed. This testing was done with no other work or traf-
fic flows on the systems. As a point of comparison, network trac flows
were started to all of the VMs on each host, and the migration exercise
was run again. The result was that the time required to migrate the VMs
was only minimally aected.
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• Internal and external trac do not need to share a physical
connection. DMZs can be configured on dierent network adapters
to isolate internal trac from external trac as security needs dictate.
•Back-end services are handled by VMware ESX. Administrative
trac and other back-end services are handled by a separate
networking stack managed by the VMkernel, providing further
isolation from VM trac, even on the same physical connection.
TRAFFIC SEGMENTATION AND ENSURING BANDWIDTH
10GbE provides enough bandwidth for multiple trac types to coex-
ist on a single port, and in fact, in many cases Quality of Service (QoS)
requirements can be met simply by the availability of large amounts of
bandwidth. The presence of sucient bandwidth can also dramatically
improve the speed of live VM migration using VMotion, removing poten-
tial bottlenecks for greater overall performance. Beyond the general
availability of significant bandwidth, however, trac segmentation can
provide dedicated bandwidth for each class of network trac.
While segmenting trac flows onto discreet GbE connections is also a
viable means of providing dedicated bandwidth to a specific trac type
or function, doing so has distinct shortcomings. For example, allocating
two GbE connections to a VM trac port group provides a potential of 2
Gbps of dedicated bandwidth, but if additional bandwidth is needed for
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The presence of sucient bandwidth can also dramatically improve
the speed of live VM migration using VMotion, removing potential
bottlenecks for greater overall performance.