Providing compute, bandwidth and storage on demand is among the first priorities Sunay Tripathi argues for in his recent blog, " Crossbow: Virtualized Switching and Performance.
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There he also argues for a move to open standards, open technology and
off-the-shelf hardware as a means to realizing his aim. "The cloud
needs to be built in such a manner that a user can take his physical
network and migrate it to an operator's cloud and at the same time have
the ability to build their own clouds and migrate stuff between the
two," he writes.
So, open networking is what makes this possible, he continues,
leaving no room for custom Asics and protocols. OpenSolaris and
Crossbow are giant steps in the direction of achieving the promise of
cloud computing, Tripathi implies, as he proceeds to identify some of
the distinctive features of Crossbow:
Crossbow leverages NIC hardware switching and features to deliver
isolation and performance for virtual machines. Crossbow not only
includes hardware- and software-based VNICs and switches, it also
offers virtualized routers, load balancer, and firewalls. The Virtual
Network Machines can be created using Crossbow and Solaris Zones and
have pretty amazing performance. All these are connected together using
the Crossbow Virtual Wire. No fancy and expensive virtualized switches
are necessary to create and use Virtual Wire.
Crossbow uses hardware virtualized lanes to scale multiples of 10 gig traffic with off-the-shelf hardware.
Hardware-based VNICs and Switching
Tripathi provides an illustration in his blog that shows how
crossbow VNICs are built on top of real NIC hardware and how switching
is done in hardware where possible. Further, Crossbow does have a full
featured software layer where it can do software VNICs and switching as
well. The hardware is leveraged when available. It's important to note
that most of the NIC vendors do ship with the necessary NIC classifiers
and Rx/Tx rings and, which are pretty much mandatory for the 10 gig
NICs that form the backbone for a cloud. Crossbow Hardware-based VNICs
The Crossbow Virtual Wire technology allows a person to convert
a full featured physical network (multiple subnets, switches and
routers) and configure it within one or more hosts, Tripathi points
out. This is the key to moving virtualized networks in and out of the
cloud. The blog includes a link to a workshop on how to virtualize a
two subnet physical network with multiple switches and different link
speeds that is connected via a router all in a single box. Virtual Wire: Network in a Box Scaling and Performance
Tripathi points out that Crossbow leverages the NIC's features pretty
aggressively to create virtualization lanes that help traffic scale
across large numbers of cores and threads. For people wanting to build
real or virtual appliances using OpenSolaris, the performance and
scaling across 10 Gig NICs is essential. Again, the blog presents a
figure that illustrates an overview of hardware lanes.