Posts Tagged ‘Hyper-V’

Advanced Hyper-V replication configuration

August 9, 2013 Leave a comment


In the last post, I presented the Capacity Planner for Hyper-V Replica and in the documentation, I discovered that this tool can suggest a value for the parallel machines number to be transferred.

Rapidly, I asked Google about this parameter and bingo! A very nice article from Microsoft that describes more parameters to configure :

  • DisableCertRevocationCheck
  • MaximumActiveTransfers
  • ApplyVHDLimit
  • ApplyVMLimit
  • ApplyChangeReplicaDiskThrottle

All these parameters can be configured through the registry.



The new features of Windows 2012 R2 Hyper-V explained by Aidan Finn

August 2, 2013 Leave a comment

Hi again!

I was searching for the new capabilities of Windows 2012 R2 Hyper-V and I have found this post of the famous Aidan Finn. Most of the new features are explained in the same blog. A real gold mine for the virtualization geeks.


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: ,

Hyper-V architecture can be misleading

July 18, 2012 Leave a comment

In this post, I will speak about a very important topic that could decrease you virtual infrastructure performances if you are using Hyper-V or you intend to use it.

First of all, during working on a SCOM project, I wanted to try some new features in a test environment. But I had just one server (HP DL 380 with 16Go) to do it.

For this reason, I have thought about virtualizing (using Hyper-V) a domain controller on the same server before installing SCOM. The benefit of installing Hyper-V is so obvious: The Hypervisor starts before any virtual machine and all the virtual machines start at the same time even the parent partition. So, logically and generally, no problems with domain authentications if you are using domain accounts for the services.

However, with 14Go, I have noticed that my SCOM is so lento! So what’s the matter?

The response is in my introduction: Hyper-V relies on its parent partition to deliver virtualization services and drivers access to the child partitions:

Unfortunately, Hyper-V role allows you to install anything on the parent partition. And according to the Microsoft best practices, it is recommended to install the core edition in such way to limit you. So the parent partition is not dedicated for installing production products like SQL Server, SCOM, SharePoint, etc. And even you have to do it for test purposes, think about following the best practices like using the disk passthrough for the databases.

If we take a look on the ESX architecture we’ll see that this problem could not occur easily. As the VMKernel does not allow anything to be installed, the performances headache is eliminated.

To solve the problem, you have to use the ancient virtualization technology that relies on the host operating system. The advantage of this solution is that your test environment is not virtualized and in this case, you enjoy entirely the benefits of your hardware performances. Virtual Box can be so useful in such situations. You have just to configure automatic starts of your virtual machines (domain controller for example) and authentication latencies of the services that use domain or service accounts for example.