One of my customers phoned me up today and wanted to discuss the fact that XenServer Enterprise is available for free. I wasn’t prepared at all which makes a discussion like this very “interesting” to say the least, especially because I’m not a competitive expert.

I answered the customers question by asking a question: Do you really think the product is free and enterprise ready?

The customer referred me to this blog article by Mr. Crosby, the article clearly states:”…will find in XenServer a complete free Enterprise Virtual Infrastructure solution”.

This particular customer is a heavy DRS user, I’m talking about multiple clusters with each at least 3 resource pools which contains at least 100 VM’s each. The current version of XenServer doesn’t have the DRS implementation the customer currently uses, but not only doesn’t the current version have this feature… the next version will also not have this feature. DRS will be part of Xenserver Essentials, in other words the paid management tool.

I’m just a consultant, I might be wrong… but most of my customers consider DRS to be an Enterprise feature. But it’s actually not only DRS that’s missing from the Free “Enterprise” Virtual Infrastructure solution… what about High Availability? I could be wrong again but all my customers seem to agree that High Availability is an Enterprise feature. Again HA is available, but it has been shifted from XenServer Enterprise to XenServer Essentials, yes the paid version… and what about support on the Free version, can’t seem to find any info on support.

Now I’m not going to tell you guys that VMware has the best product or that XenServer doesn’t cut it in an enterprise environment because that depends on your needs and wants. I do want to stress that not everything is what it seems to be and don’t believe everything you read.

Project Virtual Reality Check (VRC) is a joint venture of Log•in Consultants and PQR, who have researched the optimal configuration for the different available hypervisors (hardware virtualization layers). The project arises from the growing demand for a founded advice on how to virtualise Terminal Server and Virtual Desktop (VDI) workloads. Through a number of researches, Log•in Consultants and PQR show you the scaling possibilities for Terminal Server environments as well as Virtual Desktops.

Most of the talk about VRC was of course on the results. (You need to login to be able to download the pdf’s.) In short: VMware ESX beats Citrix Xenserver on VDI deployments and Citrix Xenserver beats VMware ESX on XenApp deployments. I’ve heard a lot of people argue about the fact if the used test methodology was correct and if the used optimization for ESX was necessary or not. (Mem.ShareScanGhz and Mem.AllocHighThreshold, unnecessary in my opinion.) But VRC will start testing again without the “optimization” to see if these effected the results or not.

A week after the VRC published there findings Team VROOM, VMware’s Performance Team, also published a blog article on XenApp performance. They also used ESX 3.5 and Xenserver 5. But the results they harvested from their test had a different conclusion. Of course their test methodology and tools were different from Project VRC’s so it’s hard, and in my opinion impossible, to compare them. I guess both test show that you CAN virtualize a XenApp environment with little extra overhead, that’s the most important thing to remember.

Please visit both VROOM and Project VRC and start reading these excellent articles. Both have put a lot of time in testing and writing and definitely deserve your full attention, and feedback/comments!