cycles enough to make it worthwhile to
burn switching cycles inside the server.
If I’m a network guy in IT, I better
learn the concept of port groups, how
VMware, Xen, and others work much
more intensely, and then figure out
how to get control of the password and
get on the edge. Those folks now have
options that they have never had before.
The guys managing the servers are
not qualified to lead on this because
they don’t understand the concept of
a single shared network. They think in
terms of bandwidth and VPLS (virtual
private LAN service) instead of thinking about the network as one system
that everybody shares and is way oversubscribed.
ReDDy: We are moving to Xen and
building a new data center architecture with flat networks. We tried to use
VLANs, but we have taken a different
approach and are going to a flat layer 2
network. On top of this we are building
an open vSwitch model placing everything in the fabric on the server.
My problem is in responding to
the service requirements of my applications and addressing things such
as latency and throughput. The data
needed to address these issues is not
available from either a network virtualization solution or the hypervisor.
Also, my uplink from the switches is
10 gigabits per second or multiple 10
gigabits per second, but my NICs are
only one gig. If I run 10 VMs on a box,
then all of the bandwidth aggregates
on one or two NICs.
neaSe: You guys are cheap. If you
went to a backplane, then you would
get a lot more bandwidth out of those
servers. A KR signal on a backplane is
how you get a cheap copper trace for
caSaDo: Going forward, a new network layer is opening up so you can
take advantage of virtualization. Traditional networking vendors certainly do
not control it today and may not control it in the future. The implications
are that it may not matter what networking hardware you purchase, but it
may matter much more what network
virtualization software you choose.
If you like the cost point and the service and operations model of the cloud,
then look at Eucalyptus, Amazon, Rack-space, and so forth, and see how they
build out their infrastructure. Today
mass interest in
virtualizing the data
center is breaking
a lot of traditional
logical bounds. you
need to concentrate
on what you’re
trying to achieve
in your data center
and what key
trying to preserve.
that is the only way you can get these
types of flexibility and per-port costs.
It would be interesting to compare
a vertically integrated enterprise with
something like Amazon EC2 (Elastic
Compute Cloud) in terms of cost per
port and efficiency.
BeeLeR: The guys who run infrastructure for Google told us that the difference between running their own infrastructure and running their stuff on
Amazon was small enough that it really
made them think about whether they
wanted to continue to do it themselves.
caSaDo: We have seen close to two
orders of magnitude difference between a vertically integrated solution
and something like EC2.
BeeLeR: The relevance here is that
while these issues may not affect you
today as a practitioner, you should understand them because they will affect
you tomorrow. In this way you can make
intelligent investments that will not
preclude you from taking advantage of
these kinds of benefits in the future.
caSaDo: The leverage point for vertical integration has always come from
the networking vendors. It was lost a
long time ago on the servers. Someone
who offers a full solution is going to be
a networking vendor. If you’re making
a purchasing decision, then you don’t
have to blindly follow the legacy architectures.
I do not believe that owners of existing network infrastructure need to
worry about the hardware they already
have in place. Chances are your existing network infrastructure provides
adequate bandwidth. Longer term,
networking functions are being pulled
into software, and you can probably
keep your infrastructure. The reason
you buy hardware the next time will be
because you need more bandwidth or
less latency. It will not be because you
need some virtualization function.
TaVakoLi: We get caught up on
whether one is implementing a new
data center from scratch or is incrementally adding to an existing one.
For a new data center, there are several things to keep in mind. Number
one, if you’re planning for the next five
years, understand how you are going
to avoid focusing on “rack versus row
versus data center.” Architect the data
center to minimize location-depen-dent constraints but still be able to