& cplSiteName &

Virtual Machine Fabric Extender Performance

Light Reading
Series Column
Light Reading
1/29/2012
50%
50%

EXECUTIVE SUMMARY: The Cisco UCS’s Virtual Machine Fabric Extender (VM-FEX) offers consistently increased network performance operations compared to virtual distributed switch installations.


In a standard Local Area Network, various hosts, laptops and PCs typically connect to a Layer 2 switch that aggregates the physical stations before handing them off to a router. Communication between two hosts on the same LAN can be done directly without reaching the router. Similarly, a virtual switching instance passes traffic either to a VM sitting in the same hardware, or pushes it out the physical port. Virtual Switches (such as the Cisco Nexus 1000v or VMware’s vNetwork Distributed Switch) operations are done in software and Virtual Switches (such as the Cisco Nexus 1000v or VMware’s vNetwork Distributed Switch) operations are done in software and therefore take resources away from the virtual machines hosted on the blade. Reducing the amount of resources available to the VMs.

Cisco's Nexus 1000v has a rich set of capabilities such as VLAN aggregation, forwarding policies and security. Cisco, however, found that not all VM installations require these features, and in such cases it makes sense to save the resources taken by the virtual switch and appropriate them to the customer needs.

Cisco claimed that their Virtual Machine Fabric Extender (VM-FEX) in VMDirect mode replaces the switch and shows a significant increase in CPU performance for network intensive applications. VM-FEX, installed on VMWare ESX 5.0, enables all VM traffic to be automatically sent out on the UCS's Virtual Interface Card (VIC). This meant more traffic on the physical blade network interface, but reduced CPU usage, which is typically the VM bottleneck. To verify that the VM-FEX really frees up CPU resources, we ran a series of tests comparing a VM-FEX-enabled UCS blade to a Nexus 1000v virtual switch setup. Both UCS blade installations were identical in all aspects apart from the use of the VM-FEX in one and Nexus 1000v in the other.

We started comparing the performance between the two setups using Ixia’s virtual tools. We installed four Ixia IxNetwork VMs on each of the two UCS blades and sent 3,333 Mbit/s of traffic from each of the first three VMs, toward the fourth for 120 seconds using 1,500-byte frames. In the VM-FEX case we recorded 2.186 percent frame loss, while in the distributed switch environment we recorded 16.19 percent frame loss.

We expected loss in both cases, given the almost 10Gbit/s load we were transmitting in the virtual space. The load was required in order to really keep the CPU busy. We deduced from this initial test result that in the VM-FEX environment less resources were used, which is why the frame loss we recorded was smaller than the loss recorded in the virtual distributed switch setup.

For the next test setup we installed one IxLoad VM on each of the two blades. We configured both IxLoad VMs as HTTP clients that requested traffic from a Web server Cisco configured. The IxLoad emulated clients were configured to try and use as much bandwidth as possible by requesting 10 different objects from 10 URLs repeatedly. The VM-FEX setup reached 9.87 Gbit/s while the distributed switch reached 7.78 Gbit/s. The CPU usage was also significantly higher in the virtual distributed switch setup when compared to the VM-FEX setup.

Using the Ixia test tools we recorded the performance difference we expected. Cisco recommended that we perform a test that relies more heavily on the Storage Area Network (SAN). For this test, Cisco helped us to set up 10 VMs on each of the two setups, and install IOmeter on each virtual machine. IOmeter was configured to read blocks from an iSCSI-based SAN as fast as it possibly could. We manually started each of the twenty IOmeter instances, and after 10 minutes we manually stopped each of them. At the end, we looked at three statistics -- Input/Output Operations per Second, Data Rate, and Average Response Time -- all three averaged across the 10 VMs in each setup. The VM-FEX performance was indeed higher for all three metrics. The data is shown in the graph below:

We were still curious what the difference would be when someone is running a common task on a single VM. We wrote a script to use the open source program mplayer to encode a DVD image file that was stored in the SAN into mpeg (for private use of course). We wrote two versions of the script -- one performed an additional round of encoding. The results of this test run actually showed that the act of fetching blocks off the network-attached DVD were not too resource intensive as the VM-FEX setup required only marginally less time to perform the encoding than the virtual distributed switch setup.

Perhaps the most interesting metric was not the performance, but rather the CPU utilization. How much of the CPU was used for the operation, and how much was left over for other operations and other users? As shown below, the VM-FEX setup used far less of CPU resources in all cases. This was expected, since the CPU was skipping an entire layer of virtual switching, and this was, after all, exactly what Cisco wanted to demonstrate.


Next Page: Virtual Security Gateway
Previous Page: Unified Fabric (UF) – UCS Manager


Back to the Cisco Test Main Page

(0)  | 
Comment  | 
Print  | 
Newest First  |  Oldest First  |  Threaded View        ADD A COMMENT
From The Founder
Kicking off BCE 2017, Light Reading founder Steve Saunders lays blame for NFV's slow ramp-up and urges telecom to return to old-fashioned standards building and interoperability.
Flash Poll
Live Streaming Video
Charting the CSP's Future
Six different communications service providers join to debate their visions of the future CSP, following a landmark presentation from AT&T on its massive virtualization efforts and a look back on where the telecom industry has been and where it's going from two industry veterans.
Women in Comms Introduction Videos
Infinera's Sales Director Paints Tech's Big Picture

6|21|17   |   4:14   |   (1) comment


Shannon Williams, Infinera's director of sales, shares how she achieves work's many balancing acts -- between her role and the broader company, today and tomorrow's tech and more.
LRTV Custom TV
SD-WAN Innovation & Trends

6|20|17   |     |   (0) comments


Versa CEO Kelly Ahuja discusses with Carol Wilson the current status and trends in the SD-WAN market, Versa's innovation around building a software platform with broad contextualization, and the advantages that startups can bring to the SD-WAN market.
LRTV Interviews
Ovum's Dario Talmesio on 5G in Europe

6|20|17   |   02:16   |   (0) comments


At 5G World 2017, Dario Talmesio, principal analyst and practice leader on Ovum's fixed and mobile telecoms European team, explains the emerging trends amongst European operators as they prepare for 5G.
LRTV Custom TV
Putting Power on a Pedestal

6|19|17   |     |   (0) comments


ARRIS's John Ulm says a major accomplishment of SCTE•ISBE's Energy 2020 program is increased focus on power cost and consumption, including inclusion of energy requirements in operators' RFPs and RFIs.
LRTV Custom TV
Gigabit Access: The Last-Mile Pipe for All Future Services

6|19|17   |     |   (0) comments


A Gigabit access platform being deployed today must be able to deliver all types of services to an increasing number of devices. A non-blocking architecture is necessary to support the ever-increasing growth in bandwidth demand. The Huawei Gigabit access solution is based on a distributed design that is fully scalable to deliver a unprecedented performance.
LRTV Custom TV
Key Factors to Successfully Deploy an SD-WAN Service

6|19|17   |     |   (0) comments


As service providers transition their SD-WAN solution from trials and limited deployments into production at large scale, there are important considerations to successfully operationalize these solutions and realize their full potential, without adding complexity, introducing uncertainty or disrupting current business operations. Sunil Khandekar, CEO and Founder ...
LRTV Custom TV
IoT Solutions: Rational Exuberance

6|19|17   |     |   (0) comments


IoT solutions are morphing from hype into viable business opportunities. Huawei has the platform and ecosystem support to help carriers successfully address new business opportunities in the IoT space.
LRTV Custom TV
Realizing ICN as a Network Slice for Mobile Data Distribution

6|19|17   |     |   (1) comment


Network slicing in 5G allows the potential introduction of new network architectures such as Information-centric Networks (ICN) as a slice, managed over a shared pool of compute, storage and bandwidth resource. Services over an ICN slice can benefit from many architectural features such as Name Based Networking, Security, Multicasting, Multi-homing, Mobility, ...
LRTV Interviews
Ovum's Mike Roberts on 5G Uptake

6|19|17   |   04:08   |   (0) comments


Mike Roberts, research director for Ovum's service provider markets group, explains why he has boosted his 5G subscriptions forecast.
LRTV Interviews
AT&T's Hubbard on Intersection of SD-WAN & MPLS

6|15|17   |     |   (0) comments


Rick Hubbard, SVP of Network Product Management for AT&T Business Solutions, discusses how AT&T's approach to SD-WAN fits in with its overall virtualization strategy, explains how SD-WAN can improve enterprise customers' use of the cloud and addresses the intersection of SD-WAN and MPLS.
Telecom Innovators Video Showcase
Keep Connected IoT Devices Under Control With Allot

6|15|17   |     |   (0) comments


Allot AVP of International Pre-Sales, Daniel Keidar, explains how communications service providers can protect infrastructure and service availability from flooding attacks caused by malfunctioning or bot-infected devices connected to their network.
LRTV Custom TV
ZTE 5G World Highlights

6|15|17   |     |   (0) comments


ZTE showcases its leading 5G innovations at 5G World in London.
Upcoming Live Events
October 18, 2017, Colorado Convention Center - Denver, CO
November 1, 2017, The Montcalm Marble Arch
November 1, 2017, The Montcalm Marble Arch
November 30, 2017, The Westin Times Square
All Upcoming Live Events
Infographics
With the mobile ecosystem becoming increasingly vulnerable to security threats, AdaptiveMobile has laid out some of the key considerations for the wireless community.
Hot Topics
Verizon Warns of $500M Hit From Yahoo Deal
Iain Morris, News Editor, 6/16/2017
Netflix's Lesson in Culture Expectation Settings
Sarah Thomas, Director, Women in Comms, 6/21/2017
Kalanick Steps Down as Uber CEO
Sarah Thomas, Director, Women in Comms, 6/21/2017
BT Tech Chief Makes Plea to 5G Chip Vendors
Ray Le Maistre, International Group Editor, 6/20/2017
Like Us on Facebook
Twitter Feed
BETWEEN THE CEOs - Executive Interviews
Following a recent board meeting, the New IP Agency (NIA) has a new strategy to help accelerate the adoption of NFV capabilities, explains the Agency's Founder and Secretary, Steve Saunders.
One of the nice bits of my job (other than the teeny tiny salary, obviously) is that I get to pick and choose who I interview for this slot on the Light Reading home ...
Animals with Phones
Live Digital Audio

Playing it safe can only get you so far. Sometimes the biggest bets have the biggest payouts, and that is true in your career as well. For this radio show, Caroline Chan, general manager of the 5G Infrastructure Division of the Network Platform Group at Intel, will share her own personal story of how she successfully took big bets to build a successful career, as well as offer advice on how you can do the same. We’ll cover everything from how to overcome fear and manage risk, how to be prepared for where technology is going in the future and how to structure your career in a way to ensure you keep progressing. Chan, a seasoned telecom veteran and effective risk taker herself, will also leave plenty of time to answer all your questions live on the air.