& 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
Educational Resources
sponsor supplied content
Educational Resources Archive
From The Founder
Cisco's Conrad Clemson, recently promoted to head up the company's Service Provider Apps & Platforms developments, talks to Light Reading's Founder and CEO Steve Saunders about how he's bringing cloud video, mobile and virtualization together to empower network operators.
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.
LRTV Custom TV
What WTTX Can Deliver

2|23|17   |     |   (0) comments


Mohamed Madkour explains the benefits of WTTX while Dimitris Mavrakis discusses the challenges of delivering home broadband access.
LRTV Custom TV
Huawei on Mobile Broadband

2|23|17   |     |   (0) comments


Mohamed Madkour shares his vision on MBB for the next three years.
LRTV Custom TV
Analysys Mason Talks About the Future of Digital Operations

2|23|17   |     |   (0) comments


The future of digital operations has three key aspects: 1. Highly automated operations for both service and network; 2. Highly converged BSS/OSS for business and resources; 3. Highly merged management and control for real-time cloud native operations.
LRTV Interviews
Software Trends in the Telecom Sector

2|23|17   |   03:40   |   (0) comments


Heavy Reading senior analyst James Crawshaw talks with Telecoms.com Editorial Director Scott Bicheno about trends and developments in the telecoms software sector and what to expect at MWC 2017.
LRTV Custom TV
Huawei's Pre-MWC Analyst Briefing 2017 Highlights

2|22|17   |     |   (0) comments


Huawei shares its vision for this year's MWC.
LRTV Interviews
MWC17: 5G, Cloud RAN & More

2|21|17   |   04:35   |   (0) comments


Ovum Senior Analyst Julian Bright talks to Scott Bicheno from Telecoms.com about all things MWC, including Cloud RAN, Huawei's pitch to the industry and the road to 5G.
LRTV Interviews
MWC 2017's Key 2-Letter Terms

2|20|17   |   08:29   |   (1) comment


5G, AI, VR... these are just some of the two-letter terms that will dominate show-floor chat at MWC 2017 in Barcelona, according to these two blow-hards (a.k.a. Scott Bicheno of Telecoms.com and Light Reading's Ray Le Maistre). And then there's PB...
LRTV Interviews
Key Trends for Mobile Operators in Developing Markets

2|20|17   |   06:37   |   (0) comments


Ovum's Matthew Reed talks to Scott Bicheno from Telecoms.com about the challenges and opportunities facing mobile operators in the developing markets of Africa and the Middle East.
LRTV Documentaries
YouTube Takes on Facebook Live-Streaming

2|17|17   |     |   (0) comments


Popular 'YouTubers' will be the first to get the new service on their smartphones. You have been warned.
LRTV Custom TV
Open Source NFV/SDN Automation

2|17|17   |   05:54   |   (0) comments


AT&T ECOMP (Enhanced Control, Orchestration, Management and Policy) code is transitioning into the Linux Foundation for placement into open source. In this video, Carol Wilson provides an update on the maturation of open source ECOMP and meets with industry leaders from AT&T, Bell Canada, Orange, Linux Foundation and Amdocs to discuss what this means for the ...
LRTV Documentaries
Uber & NASA Collaborate on Flying Car Project

2|16|17   |     |   (0) comments


Is Uber for real? Well, it's hired NASA engineer Mark Moore to lead the project, and he wouldn't come cheap.
LRTV Documentaries
Zuckerberg Tries Out the Oculus Rift VR Glove

2|15|17   |     |   (0) comments


Facebook CEO shows off a new way to interact with the Oculus Rift virtual reality headset: an Oculus glove.
Upcoming Live Events
March 21-22, 2017, The Curtis Hotel, Denver, CO
March 22, 2017, The Curtis Hotel, Denver, CO
March 22, 2017, The Curtis Hotel, Denver, CO
May 15-17, 2017, Austin Convention Center, Austin, TX
May 15, 2017, Austin Convention Center - Austin, TX
June 6, 2017, The Joule Hotel, Dallas, TX
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
Broadband Has a Problem on the Pole
Mari Silbey, Senior Editor, Cable/Video, 2/21/2017
Uber's HR Nightmare: Company Investigates Sexual Harassment Claims
Sarah Thomas, Director, Women in Comms, 2/21/2017
Is the Time Right for a Cisco/Ericsson Wedding?
Ray Le Maistre, Editor-in-chief, 2/17/2017
Verizon to Start Fixed 5G Customer Trials in April
Dan Jones, Mobile Editor, 2/22/2017
Nice to See at Least One CSP Taking My Advice
Mitch Wagner, Editor, Enterprise Cloud, 2/17/2017
Like Us on Facebook
Twitter Feed
BETWEEN THE CEOs - Executive Interviews
Light Reading founder and CEO Steve Saunders chats with Sportlogiq CEO Craig Buntin about sports data analysis.
Eyal Waldman, CEO of Mellanox Technologies, speaks to Steve Saunders, CEO of Light Reading, for an exclusive interview about the 100 GB cable challenge, cybersecurity and much more.
Animals with Phones
No One Likes This Click Here
Take a hint!
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.