This topic is specifically talk about the networking concept in VM infrastructure. In most of the cases we discuss and Virtualization and Consolidation, we always thought about number of servers we reduce in the data center, the powers we save as well as others facts. Some how, I could see most of the users today who may had already in the production for little while, and will start realize about some performance issues from the network, storage and servers perspective. WIth that particular challenges and reason, we start to hear these groups are trying to tell the customers or users, if you do want to run it on VM, it meant there is performance scarification.

I am strongly disagreed with these comments as most of us know that the reason of consolidate and virtualization, is not for performance reduce, is really to improve efficiency and utilization of the hardware that we purchased. Networking play a big parts in VM infrastructure and most of the time, it did become the performance bottle neck for most users. Let me talk about some example below.

1 of the case i saw here, which the engineer configure it’s ESX in to a server which only have 2 physical NIC connected for VMnetwork interface to allow VM to be connected to the production network. There is more than 10 VMs on the ESX servers which connected to the 2 gigabits NIC and share among each others. In physical environment, for 10 physical servers, they always get 1gb per servers and is not in shared condition. But now, since virtualized, they need to share 2gb with 10 VM. Guess what, the users start complaining slow performance on the network file transfer, the backup through Network is slow as well as any reason that the network slowing down due to the high peak bandwidth utilization from any of the VM which shared on the 2 NICs. Not only the NIC causing the performance issues, and the switches uplink to the DC switches had also another thing you may need to keep an eye on. No matter how many gigabits connection you connected your servers through, it will still depend of the total uplink for your switches to route the traffic to the DC.

In this case, they not really figure out the performance issues as they won’t notice this performance bottleneck in the performance chart from Virtual Center. Most of the time, only the network guys will able to identified these issues. It really hit hard to some of the engineer which push hard on the virtualization, but it did become performance sacrification to the customers at the end. I will not want this to happen for myself, as we had invested SAN storage & High capacity servers which is not cheap solution.

Therefore, I will recommend that to deploy the VM Infrastructure in to enterprise environment in Data Center, we should always plan ahead including the Networking conditions. Again, Virtualization not meant performance sacrification, and virtualization do provide a lot of benefits which physical servers don’t.