-3

If you have both Windows and Linux on the same VM, will data move between these two OS more efficiently than if they were on two separate VM connected by a single switch?

I currently have a Windows VM on one physical server and Linux on another. A Windows app HTTP posts data to a Linux app. The Linux app also posts data to the Windows app. Both applications have a dedicated IP address.

If I move both VMs to the same physical server, will efficiency be gained? Will HTTP posts between both apps still create network traffic? I really have no idea what effect to expect from network latency.

Both applications will still require their own dedicated IP address. Please assume that the single physical server will have more than enough RAM and CPU available at all times.

Thank you

Caroline Beltran
  • 275
  • 3
  • 11
  • Another use case could be that you have a Windows server that needs to communicate with a database hosting on Linux. Someone (like me) with very little network knowledge might assume that efficiency would be gained by having both VMs on the same physical server rather than having both VMs on different physical servers. – Caroline Beltran Oct 13 '15 at 16:12

1 Answers1

1

Depending on the networking model of the hypervisor in use, if both VM's are on the same metal then network traffic can be contained within the virtual switch or bridge that the physical hosts connect the VM's to. This will potentially decrease network latency by a tiny amount when compared to cabled local network with a couple of switches / routers.

But the difference will be so small, its not worth thinking or worrying about.

Network traffic still exists between your applications since you are leveraging IP connectivity for communication.

tomstephens89
  • 981
  • 1
  • 11
  • 23
  • thank you. This is exactly what I wanted to know. In this case, I will not bother moving both VMs to a single physical server. Thank you. – Caroline Beltran Oct 13 '15 at 16:05
  • The latency cost of going across a single switch is not always negligible. I have an application where I tested running application and database on two separate computers connected by 1Gbit/s Ethernet with the two computers separated by only a single switch. It was measurably slower than running the application on the same computer as the database. Two VM on a single computer can be expected to lie somewhere between my two scenarios because going between two VMs also add some latency. – kasperd Oct 13 '15 at 19:27
  • If your network performance is a concern, its a good idea to take a look at your network set up and possibly make some performance modifications to the configuration in order to enhance your application performance. – tomstephens89 Oct 13 '15 at 19:33