I have seen tons of articles talking about the differences between VMware ESX & VMware ESXi, but I have not seen many that discuss when to use them. I have noticed that many of my customers get even more confused when reading comparisons between the two, as not all of them have deep understanding of the Virtualization Technology. That means they got to know the differences, but still wondering which one is best fit for their environments. Below is few rules that can put you on the right path.

– Do you need a free but reliable Virtualization platform as you don’t have a budget? or maybe you wanna use it for non critical applications? maybe you don’t want to pay for fancy features or an official support. In this case VMware ESXi is for you. As ESXi offer a free version, where a license can be applied to it at a later stage when you need to go fancier or require official support.

– Is security & reducing the required patching time is one of your main concerns? then you should consider using VMware ESXi as it does not have a service console which requires most of the patching time.

– Do you hate to waste resources used to run the service console, then ESXi for you?

Hmmm, you might think I am advertising the VMware ESXi over ESX. I am not, but as per VMware road map it seems ESXi will be the way to the future. Unfortunately though before going with VMware ESXi there are certain limitation that you will have to take into your consideration:

– VMware ESXi does not have a service console, which means if you are going to need the service console to run some odd application in there or some batching process, you would need to use VMware ESX. Though I don’t recommend running anything in the service console, as it will affect the speed you can apply upgrades & always having to ensure your apps running in the service console is compatible with the new update or VMware release. You don’t need to go into this headache, unless you really have to.

– Always check if your required backup, replication, monitoring or any other add-on software you are planning to obtain is supporting VMware ESXi. If it does not, then try to find a good alternative. If you must use a software which still does not ESXi, then you are again stuck with VMware ESX. A good note though, most software vendors today are supporting ESXi. Even software vendors who still not supporting ESXi, they will support it in the near future as they know it will be the way to go.

If you are not affected by the last two limitations of VMware ESXi, then ESXi should be the way to go. In the other hand, if you require one of these two then you must go with VMware ESX. A final note, I can see these two limitations vanishing in the very near future.

I hope this have been helpful, & enjoy the rest of the day. If I have missed something & you would love to add it. Please leave me a note in the comments area.