Bye bye Citrix XenServer

As we are in the week of the obituaries, let’s do another one. A few weeks ago when vSphere 5.5 was release I updated our Enterprise Hypervisor Comparison. As Citrix and Red Hat both had released a new version of their hypervisor product I also added those. Normally I only need to check for new features added or product limits which have been upgraded. But this time was different!

In the column with the new Citrix XenServer 6.2 I had to remove feature which were previously included in the product. WTF?

I rarely come across any XenServer deployments and when I speak to colleagues, customers, etc. I often hear Citrix XenServer is dead. Based on the number of XenServer deployments I see and the number of customers changing to Hyper-V or vSphere this seems to support this theory. Instead of adding new features and upgrading product limits, I had to retire numerous features.

Features retired in XenServer 6.2:

  • Workload Balancing and associated functionality (e.g. power-consumption based consolidation);
  • XenServer plug-in for Microsoft’s System Center Operations Manager;
  • Virtual Machine Protection and Recovery (VMPR);
  • Web Self Service;
  • XenConvert (P2V).

Features with no further development and removal in future releases:

  • Microsoft System Center Virtual Machine Manager (SCVMM) support;
  • Integrated StorageLink (iSL);
  • Distributed Virtual Switch (vSwitch) Controller (DVSC). The Open vSwitch remains fully supported and developed.


It has never been a secret that Microsoft and Citrix joined forces but as expected Citrix XenServer had no place there as Microsoft invested big on Hyper-V. But now it seems that Citrix has killed XenServer. With version 6.2 they moved XenServer to a fully open source model essentially giving it back to the community. Of course much of XenServer already was open source, using code from the Xen Project, Linux kernel and the Cloud Platform (XCP) initiative. But with the retirement of many existing features it seems that Citrix is stripping XenServer from all Citrix add-ons before giving the basic core back to the open source community.

Citrix still delivers a supported commercial distribution of XenServer but when an identical free version is available …… At the feature and functionality level, the only difference is that the free version of  XenServer will not be able to use XenCenter for automated installation of security fixes, updates and maintenance releases. Free Citrix XenServer does include XenCenter for server management, but not patch management. I doubt many customers will buy a version of XenServer for patch management alone.

It’s interesting to see Gartner has moved Citrix outside the leaders Quadrant and placed it in the visionaries Quadrant. Visionaries in the x86 server virtualization infrastructure market have a differentiated approach or product, but they aren’t meeting their potential from an execution standpoint.

Magic Quadrant for x86 Server Virtualization Infrastructure 2012.PNGMagic Quadrant for x86 Server Virtualization Infrastructure 2013.PNG


So it looks like Citrix has given up on XenServer and is going to focus on their core business, the desktop and the ecosystem of products around it.

Within their partnership with Microsoft they cannot or may not compete with Hyper-V although XenServer has,in the past, always been a better product than Hyper-V. With the battle on application delivery intensifying, their focus needs to be on their main portfolio. VMware is targeting Citrix’s application delivery platform with VMware Horizon Workspace and on the desktop front Citrix faces two enemies. Where Microsoft Remote Desktop Services is targeting their Server BAsed Computing/XenApp platform and VMware Horizon View is battling Citrix XenDesktop.

I wonder when we will hear that Citrix finally killed XenServer …..



How does VMware vSphere 5.5 compare to the competition?

VMworld 2013.png

Yesterday VMware release vSphere 5.5 which includes many new features and enhancements, again raising the bar for the competition.

But how does VMware vSphere 5.5 relate to Microsoft Server 2012 Hyper-V, Citrix XenServer 6.2 or RedHat RHEV 3.2? Check out our new Enterprise Hypervisor comparison in which I added the new vSphere 5.5 features and enhancements.

Enterprise Hypervisor feature comparison (RHEV added)

Back by popular demand, the Enterprise Hypervisor feature comparison.

After the release of our latest comparison I’ve received a lot of requests to include RedHat’s RHEV to the comparison. Although I’ve never encountered it in enterprise environments, I decided to add it as a service to our readers.

I based the RedHat features on their 3.1 version which is in beta right now. This is because I’ve limited knowledge of the product and I received an updated comparison from one of our readers based on this version.

I hope you find the new Enterprise Hypervisor comparison useful and feel free to contact us when you have feedback for us to improve the list.

NEW Enterprise Hypervisor comparison

Two weeks ago VMware released the new version of their vSphere hypervisor, so it’s time to update our Enterprise Hypervisor comparison. It very impressive to see how quick VMware has reacted to the Hyper-V 3 announcements and has taken most of the wind out of the Microsoft sails.

I hope you find the new Enterprise Hypervisor comparison useful and feel free to contact us when you have feedback for us to improve the list.
The information on Microsoft Server 2012 Hyper-V features is very inconsistent, many different values out there.

In this version I added 10 new criteria. Many of these criteria should, in my opinion, be available in hypervisors suitable for enterprise environments.

You can find the new and improved Enterprise Hypervisor comparison here.

Last update: August 27th, 2013

StarWind Offers Free NFR Licenses for Lab Testing, Demonstration, and Training Purposes

Starwind is an innovative company and one of the first to offer an iSCSI initiator on the Microsoft Windows platform without a lot of hassle. The company offers Not For Resale (NFR) licenses to some specific groups of IT professionals.

If you hold or are one of the following:

  • VMware vExpert
  • VMware Certified Instructor (VCI)
  • Microsoft Most Valuable Professional (MVP)
  • Microsoft Certified Trainer (MCT)
  • Citrix Technology Professional (CTP)
  • Citrix Certified Instructor (CCI).

you can get a free NFR license for its best-of-breed High Availability SAN solutions software to fuel your Lab. What do you need to do?


VMware is still the best! Virtualisation Shootout april 2011 Virtualisation Shootout april 2011

Of course we all knew that already :) Paul Venezia posted an in depth article on Infoworld where he compares the four main server virtualization software competitors on a selection of criteria.

Now, you can nit-pick on the measurements he made or the criteria he has chosen, but in general I think it’s a solid test of up-to-date versions.

The best conclusions I can draw from his report are these:

VMware might not always be the cheapest, VMware might not always be the one with the highest speeds.. but VMware is still the one with the most diverse OS support (any x86 OS can be virtualized), the best management toolkit and the most reliable architecture.



New Enterprise Hypervisor comparison


Last year we published an Enterprise Hypervisor comparison and we got very positive comments and feedback on it.

During the last few weeks I received many update requests so I decided to update the old hypervisor comparison but this time I changed the setup a bit.


  • No beta or pre-release versions are used. In the last document we also compared Hyper-V R2 beta which wasn’t officially released.
    This time all software is available and no features are subject to change due to beta-test, etc.;
  • The versions used are the platinum/ultimate/fully-featured versions of the hypervisors. Product features can be limited by lower license versions;
  • No free versions have been used in this comparison.


A ‘real life’ View, XenDesktop, Microsoft VDI comparison

After attending the dutch Citrix Partner Exchange 2010 I realized that there is a lot of FUD out there:

  • in the Citrix community with regards to VMware View and PCoIP;
  • with me personally with regards to XenDesktop (no F, but a lot of UD)

This is also what we saw when Alex shared his experience with Citrix XenDesktop, which was not so positive, and we got a lot of comments comparing XenDesktop to VMware View.

But the Citrix Partner Exchange got me interested in XenDesktop and XenClient and I decided to do a little research. Then I came across Brian Maddens site to find that he had just finished his ‘Geek week VDI‘ in which he did a ‘real life’ lab-test with VMware, Citrix and Microsoft VDI. They tested all three vendor in their lab environment but added a WAN ‘simulator’ to create real life and worst case scenarios by introducing packet loss and latency.

And honestly I was surprised by some of their their conclusions. Not because I have no faith in Brian Madden but because I know Brian Madden to be a real Citrix enthusiast and a PCoIP critic. At the end he was very honest by admitting that Citrix XenDesktop looks like a mash-up of a bunch of different things, he was surprised by the simple, straightforward installation and configuration of VMware View and the good performance of PC-o-IP.

So bottom line?

  • VMware View shines because of simplicity and has good user experience even with PC-o-IP over a WAN connection.
  • XenDesktop is, at the moment, certainly the more mature and complete product but it’s complexity is a drawback.
  • And Microsoft ‘in box’ VDI? Well as expected, it’s complex, not enterprise ready and it’s no match for Citrix or VMware.

So as always, there is no clear winner, it all depends on the customer’s wishes.

Special thanks to Brian Madden and his team for creating this great VDI test!

I won’t summarize the total VDI test, you can read it yourself here but I will quote some of the conclusions which I found to be very interesting.


Yet another experience posting: Citrix XenDesktop 4 Express – part 1

Two months ago, I heard Citrix was giving away a free VDI version called XenDesktop Express for a maximum of 10 users. The general idea is that you can experience the Citrix product advantages without investing anything but time and hardware. I downloaded it but didn’t have time to actually get some hands-on experience until last Wednesday.


Oracle VM, things they do not tell

Last week a colleague, who sells applications running on an Oracle Database, had some questions regarding Oracle and running it in a Virtual Machine (VM) on top of a VMware infrastructure with a customer.

1) How to license Oracle in a virtual environment?

I pointed him to an article about licensing the Oracle software in a virtual environment I wrote some time ago.

Oracle can namely be hard- and soft partitioned, where VMware, XenServer, Hyper V and Oracle VM are all marked as soft partitioning, while looking into the way Oracle VM can be hard partitioned I stumbled on the following how to do it:

There are two methods to pin virtual CPUs. You can use the xm command to pin a guests’s virtual CPUs or you can hardcode the CPU mapping in a guest’s vm.cfg file. The difference between pinning CPUs with xm and hard coding the CPU mapping in a guest’s vm.cfg file is the persistence of the CPU mapping. CPUs that are pinned with xm are not persistent between reboots. Hard coding the CPU mapping in a guest’s vm.cfg file is persistent between reboots. To comply with Oracle’s hard partitioning policy, you must hardcode the CPU mapping in a guest’s vm.cfg file.


The real value of Project VRC

About two weeks ago I attended a session at the VMware User Group meeting here in the Netherlands about Project VRC.  After the presentation I asked myself: ‘What is the value of this project?‘.

For you who don’t know what Project VRC is:

“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.”

Don’t get me wrong: What they did was a very good initiative, it showed the performance differences between different hypervisors. Although the results were not that surprising it was good to see the validation numbers of the things we already knew.

I also think that the guys who did the project where totally surprised by the attention vendors and customers gave to the project. It was an outstanding (marketing) tool to show the value of virtualization and especially XenApp on a hypervisor. Because of this attention the whole project got out of hand. Although this was not the goal of the project, vendors and customers used it as a reference guide for vitalizing XenApp. That’s the point where I started to wonder what the real value of the project VRC was.


Project VRC: Clock drift and test results

VRCProject Virtual Reality Check finally posted a new document about previous results and possible clock drift when using the “Login Virtual Session Indexer (VSI)”.  Previous test setups and results didn’t take into account how different hypervisors handle passing time.

In my opinion this is a serious setback to Project VRC which is considered an institute in the virtualization world. People will start questioning the results when no new tests will be performed.

Below is a description from the Project VRC website explaining the new whitepaper they published on September 14th 2009. This is a must read for people that already did some testing as well as new tests. In short: ‘Because of Windows clock behavior in virtual machines the results were affected and some hypervisors may come out better than they really are.

This whitepaper is a review and reflection on previous Project VRC publications, the benchmark: “Login Virtual Session Indexer (VSI)” and Windows clock behavior within virtual machines.  This discussion is fueled by the fact that results from the individual Project VRC whitepapers are set side-by-side to compare hypervisors. Project VRC has been in discussion with both vendors and community, and performed additional research in this context. Before Project VRC can publish new results, it is important to address any questions, review the impact of this discussion and improve VSI where possible.

You can download it at

The major conclusions in this Whitepaper are:


VMware vs Citrix @ Burton Group Catalyst event

Burton Group is in their last day of their annual Catalyst Conference in San Diego (July 27 – 31, 2009). Wednesday they had their announced VMware vs Citrix battle and I just watched their video feed.

It was a very interesting ‘battle’ between VMware’s Scott Drummonds and Citrix’s Simon Crosby but I must admit that I was a bit annoyed a times. I think the the photo on the left captures the atmosphere for the debate quite well.

Simon Crosby constantly attacking VMware on various issues, but mainly on VMware’s standpoint on performance testing, and Scott Drummonds staying very relaxed, not getting into a bitch fight, throwing mud and pulling hair.


Our first XEN-Experience, a XenServer 5.5 testdrive

As I am in the final week before my holiday and all projects are finished, I thought it might be a good idea to check out the competition. So I downloaded the free version of Citrix’s XenServer 5.5 to see what the fuss is all about.

First I tried to install it on a spare desktop at home (P4 2,4GHz CPU, 2GB RAM) but this failed, probably because the CPU doesn’t supply Intel VT.

Yesterday at work I grabbed two desktops with a Core2Duo E6400 with Intel VT and 4GB of RAM and installed Citrix XenServer 5.5 on it.

XenConsoleThe installation is pretty straightforward, much like ESXi, and in about 5-10 minutes you will have a XenServer up and running. The first thing I noticed is that the console is very feature rich. We all know the yellow/gray console of an ESXi server and all you can do is basic configuration tasks like set an IP address, DNS server and default gateway, give the server its name, do a few tests and that’s about it. The console of a XenServer has a lot more features. Next to all ESXi-like features you can start and stop virtual machines, configure storage, resource pools and licensing, configure back-up, restore and updates.


Enterprise Hypervisor comparison (updated 04-06-09)

April 25th we published our Enterprise Hypervisor comparison and we got very positive comments on it. A few people were kind enough to provide us feedback so we could improve the document, thanks for that.

I collected all comments and feedback and created version 1.3 of our Enterprise Hypervisor comparison which can be found here.

Again, feel free to contact us when you have feedback for us so we can improve the list.


(Gabrie, thanks for the detailed feedback. I hope  you will find that all points are taken care of.)

Update 4-6-09: Updated to version 1.3 after feedback from Jorge

Last update: November 29th, 2011.

Enterprise Hypervisor comparison

The last few weeks many blogs and forums have spend time on hypervisor comparisons and I have read tons of articles on the subject. Many only compare hypervisors based on performance, features or cost. I think it’s a bit more complicated then that. After Citrix announced that their XenServer product is available for free I spend a fair deal of my time explaining to colleagues and clients that this is a hoax and that cost is not the only reason to base their decision on. Especially in the case of XenServer the choice and the long term effects make it a little bit more complicated.

When I read Chris Wolfe’s article on ‘Production-class Hypervisor Evaluation criteria‘ and saw his VMworld Europe 2009 presentation (DC15) I found someone who read my mind. Chris knows what he is talking about and uses the right criteria to select the right hypervisor for the job. Now you probably think ‘These guys are VMware fans so here we go again‘ but the opposite is true.

Like Chris I think every situation has its own ideal solution and you should select the hypervisor based on well-considered selection criteria and because my employer, Centric, focuses on clients with 500+ workstations/employees these criteria are Enterprise-class hypervisor selection criteria.


There is no such thing as a free lunch

XenServer Enterprise for free?

Anne Jan and I were asked last week ,while doing work at our companies  Headquarters, how we thought about Citrix giving away XenServer Enterprise for free and positions it as “XenServer a complete free Enterprise Virtual Infrastructure solution”. So I asked them what is considered “free” and what are the needs of the customer with a complete data center/enterprise virtual infrastructure?

The question arose because they wanted to know if they made the right choice for a very big company to choose VMware Infrastructure 3.5 Enterprise above  Citrix XenServer.

So looking at what customers answer me when I ask what their requirements are, are for me the best route to go, because customers are the only one who know their organization’s virtualization requirements.

Most given answers I get when I ask for the requirements are: