Posts Tagged ‘SFlow’

InMon SFlow extension for Hyper-V 3 Part 2

August 26, 2012 Leave a comment


In the last post, I have introduced the SFlow protocol and the solution developed by InMon for Hyper-V3.

Let us see in this post how to install it.

First of all, we have to understand the architecture of the InMon solution described by this image:

As you can see, InMon solution is a virtual switch extension. This new architecture provided by Hyper-V3 allows us to integrate special treatment on the network stack for QoS purposes for instance. We can for example integrate new protocols and so forth.

An other important element is the agent which is installed on each Hyper-V machine. its purpose is to send collected data from the virtual switch to a collector installed on another machine.

In our case, we’ll use the Sflow Trend provided freely by InMon on this link.

And new let us start:

  • Download the SFlow extension from this link.

  • Install the SFlow extension and agent on each Hyper-V3 machine.
  • On the parameters page, you have to introduce the collector machine, the polling interval and the sampling rate as SFlow is based on the sampling principle. For this reason we say that the data provided does not reflect  exactly your network status. these parameters can be changed through the registry.
  • After installing the agent, you have to select the appropriate virtual switches and select the extensions part to check the sFlow Traffic monitoring parameter.
  • Download sFlow Trend and install it on the collector server.
  • Wait for some minutes and launch the sFlow Tend console to discover the beautiful results.
  • Charts is one of the most important data views that allows you to analyze your network according to the Top connections and the according protocols.
Categories: Hyper-V, MS Technologies Tags:

InMon SFlow extension for Hyper-V 3 Part 1

August 21, 2012 1 comment




Today the IT infrastructures trend is to be virtual oriented. In this case, we have to monitor some typical aspects.

One of the most important elements to manage is the network health as it is the basis of the machines communication. However, our main purpose is to analyze the bandwidth used by the machines. For this reason some new protocols are defined like NetFlow and SFlow.

What about SNMP? A very interesting response can be found here :

  • SNMP can be used for real-time (i.e. every second) and although NetFlow provides beginning and end times for each flow, it isn’t nearly as real-time as SNMP. In fact, due to the active timeout issue, NetFlow really can’t provide granularity finer than 1 minute else, it sort of defeats the idea of NetFlow’s awesome aggregation. I think we are all learning about how important the active timeout is with the Cisco ASA.
  • NetFlow tells you who and with what is consuming the bandwidth, it is also much more verbose than SNMP and therefore NetFlow exports consume much more disk space for historical information
  • SNMP can be used to collect CPU and memory utilization and that just isn’t available yet using NetFlow. Notice I used the word ‘yet’. The future of NetFlow is very optimistic.

I have recently worked on a very interesting project involving Hyper-V 2 and ESXi 5.0. I have applied some best practices on the virtual machines to improve the performances like increasing the VMbus buffer size. As a switch presents some problems, I noticed a big number of dropped packets and I searched some solutions that can help me to find the origins issue.

Here I have encountered the SFlow protocol which is used to monitor and analyze the flow networks. A definition of this protocol is described by this video :

As Hyper-V3 defines an extensible structure of the VSwitch, InMon has developed SFlow extension that can be integrated n the VSwitch pipeline. In this case, we can analyze the flow networks of the machines connected to Sflow activated switches.

In the Part 2, InchaEllah, I will describe the steps to install SFlow on Hyper-V3.

Categories: Hyper-V, MS Technologies Tags: ,