Archive for March, 2010
Networking is the fourth I/O component that I will be covering in this series of performance write ups. Networking is another important component in the stack, if not well thought out, can lead to performance problems later down the road. Security is an important design consideration when planning your network configuration. One might argue that with a virtual environment your are more prone to risks since at times there is no longer a physical cabling restriction in place. If someone has the appropriate rights in virtual center, they could bridge two logical networks together, or place a virtual machine into a DMZ. VMware introduced vShields to mitigate your virtualized environment from some of these risks. By creating zones you can enforce policies that can bridge, firewall, or isolate virtual machines between network segments. When designing or upgrading your VMware environment, work closely with your network team to understand their design considerations. If possible, leverage VLAN tagging (802.1q) to eliminate excessive physical cabling to different segments.
Personally one of the most interesting components of the VMware architecture I/O stack is storage. There are a plethora of diverse storage solutions in the industry today that offer unique different ways of addressing storage performance, as well as the increase in capacity demands. Storage problems are the most common mis-configuration effecting performance that exists in VMware today. An oversaturated LUN will effect all virtual machines that share that same data store. Take this concept up a level, a group of disks (RAID group) that are saturated with I/O will negatively impact all LUNS that share those same physical spindles. Storage traditionally has been the “red headed step child” in VMware and hasn’t gotten a lot of visibility. Storage I/O bottlenecks can create serious virtual machine problems and yet it wasn’t until ESX 3.x that graphic visibility was even displayed to VMware administrators, see 2.x MUI reflects CPU and memory (Management User Interface for those newer to VMware).
I attended last months Cincinnati VMUG (VMware User Group) and was surprised to hear the responses from the audience on how many customers had not taken the plunge, and upgraded to vSphere yet. I think there were a handful of users that had just completed the upgrade. Sometimes I forget to step out of my own personal space and consider what others have going on in their own environments. If your still wondering about the upgrade, Aaron has a post on some of the benefits of going from VI3 to vSphere.
Part of the process of upgrading your existing investment is the need to upgrade all of the virtual machines to the latest and greatest virtual machine hardware version 7. Someone mentioned to me how much of a pain this was since you had to touch each virtual machine, and my response to them was “It only takes a couple of minutes”. I wanted to prove this theory in a different way, so I mulled over it and came up with a timed video clip. The song I chose is 2 minutes and 39 seconds, so I figured If I can knock this out within the amount of time it takes for the song to play, well then, mission accomplished. Read the rest of this entry »