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 …..



Cost analysis: VMware Horizon View vs Citrix XenDesktop

View vs XenDesktop

When I’m advising customers on desktop solutions it’s an obvious battle between VMware, Citrix and Microsoft.

Customers are becoming more and more cost aware due to the economic circumstances but the demand for audio/video and real time communication is growing. When Server Based Computing (SBC) is a viable option customers tend to compare Citrix XenApp to Microsoft Terminal Services.

When applications or customer demands require a VDI solution, it’s a battle between VMware Horizon View and Citrix XenDesktop.

Because companies are extremely cost aware nowadays, it’s not only a feature-based comparison but they must also look carefully at cost. Principled Technologies, compared Microsoft Windows 7 virtual desktops hosted on VMware Horizon View 5.2 and Citrix XenDesktop 5.6.

Hosted on the same physical hardware resources and using similar image rendering settings, they conducted scale testing with the Login VSI medium workload.  They found that VMware Horizon View 5.2 supported 174 Microsoft Windows 7 virtual desktop sessions at a cost per user of $483 Citrix XenDesktop 5.6 supported 175 sessions at a cost of $820 per user.


VMware continues to lead

The virtualization landscape is evolving. Nowadays two-thirds of x86 server workloads are virtualized, the market is mature and competitive and enterprises are evaluating the cost-benefits of switching technologies more than ever.

For years and years VMware has been the clear market leader but Microsoft and Citrix have been trying to close the gap. Besides those three virtual giants, RedHat, Oracle and Parallels have been trying to get a piece of the pie.

Last week Gartner published their annual Magic Quadrant for x86 Server virtualization. Let’s see how the virtualization landscape has changed in the last year.

magic quadrant 2013When we compare this magic quadrant with the one from 2012, we see that Oracle, Parallels and RedHat maintain the niche players. Personally I’ve never come across any Oracle, Parallels or RedHat virtual environments and I’ve seen my share of companies, from smaller SMB to large enterprises.

When we look at the big three, Citrix, Microsoft and VMware, we see that Citrix dropped out of the magic upper-right quadrant. Why?


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

Updated Enterprise hypervisor comparison

During the last few years we published several Enterprise Hypervisor comparisons and we got very positive comments and feedback on it. With the release of vSphere 5, XenServer 6 and a service pack for Hyper-V it was time for an update.

It very interesting to see how some of the products have improved over the years and how the three major manufacturers look at each other and copy features. But you can’t trust all manufacturers by just a simple green checkbox. Some claimed features need third party add-ons, aren’t suitable for production workloads or are only supported on a limited set of operating systems. You have to investigate further and I hope I’ve done most of that work for you with this new enterprise hypervisor comparison.


Looking forward into 2011 and beyond..

We here at hope you all had a proper start of 2011. We sure did!

But what will 2011 bring us? Some curtains have been lifted a little. We know we can expect a brand new version of vSphere in 2011. But what features will vSphere 5 have. Personally I hope we will finally see a vSphere Client for Linux/OSX with this version.

We will certainly see Citrix and Microsoft push the boundaries more and more in the desktop virtualization area. But do you think we will finally see the major shift to 64 bit in this field too? It has been predicted for years and years (some folks even mention 128 bit systems in the near future).


Comparing RemoteFX to RDP, ICA/HDX, EOP and PCoIP

One of my coworkers pointed me to a video from this years Tech-Ed Europe about VDI protocols. Bernhard Tritsch did an interesting comparison between the different remote protocols used in today’s VDI solutions. In a 60 minute session Bernhard explains the differences between location (host vs client), type (hardware vs software) rendering and compression types (lossless vs lossy).

Although the results aren’t that good for PCoIP (software version) it still is a very interesting video.

Get Microsoft Silverlight

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.


Trade in XenApp for VMware View part 2

It is always nice to see how Citrix fan-boys reacts on publications about VMware View. Especially when it comes to an comparison or XenApp for View trade in. It is often said that Citrix listens to their customers but they are seldom heard! People need simple solutions in a complex IT world. Why pay for a very high end piece of engineering like a Ferrari if I can get the job done with a Volkswagen! OK, it is nice to have a car that nobody else has and can do 320 km/h but in times were budgets are under pressure, I have a hard time defending expensive, complex and high-end solutions.

The fact that VDI is putting a significant load on the storage is true, but that counts for every VDI solutions including XenDesktop, so no differences there. Also the new upcoming version of View includes a basic profile management solution “Persona Management”. Which makes the use of linked clones a very workable solution.

When you compare installing View and XenDesktop you will see the following diagram.













When it comes down to management consoles the two solutions also look very different.


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.


Best practices XenApp on vSphere

Based on the real life results when virtualizing XenApp I thought it was about time to summarize some of the best practices for virtualizing XenApp servers.

Why we DO want to virtualize XenApp?

  1. For server consolidation:  vSphere enables scale up XenApp deployments;
  2. For mixing server editions: 32-bit and 64-bit XenApp VMs can coexist;
  3. For management: Better management through flexibility & isolation think about Change Management and VMware DRS;
  4. For high availability and disaster recovery: VMware HA and vCenter Site Recovery Manager;
  5. For less costs for server hardware, maintenance contracts, power, cooling, floor and rackspace.

Virtualizing XenApp servers is very complex. There are a lot more layers involved, like the type of hardware, the capabilities of the processor, the performance of the shared storage, the hypervisor used, the specific settings per hypervisor, operating system settings in a virtual environment, the XenApp settings in a virtual environment, the Workspace management settings in a virtual environment etc, etc.

In the following sections I tried to summarize some of the best practices we use in our projects:


VMware View & Citrix XenApp, the similarities & differences.

Last week I held a presentation for our Sales department. As we sold a lot of Citrix Xantippe over the last few years they wanted me to tell them more about the differences between a VMware View and the traditional terminal server based Citrix XenApp solution. So I made a summery about the differences and similarities. When VMware also asked me about the presentation I decided to translate it into English and share it with you all.


CDG Technical update

Yesterday, the three of us attended one of the quarterly CDG(1) Technical update sessions which was held at ‘de Glazen Ruimte‘ in Maarssen.

The three subject were:

  1. RES Software and VMware View by Bart van Winden (RES) en Ton Hermes (VMware);
  2. Citrix reduces traffic jams on the roads to and from our Dynamic Delivery Center by Marc Wagevoort (CDG);
  3. VMworld San Francisco 2009 update by Rob van der Wel.


Citrix HDX 3D with host-side GPU-based encoding

Yesterday Citrix announced HDX 3D which is an enhancement to the ICA protocol which, according to Citrix, delivers 3D applications by only using one-tenth of the bandwidth.

This is fierce competition for VMware’s PCoIP which they developed with Teradici and which VMware will demo at VMworld 2009 this week.

I have only seen the HDX 3D demo video, which can be found here, and I’m anxiously waiting for footage of the PCoIP demo at VMworld 2009 this week. I’ve seen the demo at VMworld Europe 2009 and I must say I was very impressed . On the other hand I found the Citrix videos to be very shaky/flashy/blinky. I hope (and to be honest, I think) that this is not representative of real life performance (I’m in a pro Citrix mood today ;-) ).

If you want to know what HDX 3D is and how it works please visit He can explain this much better than I can but you will have to see past the Citrix minded VMware skepticism ‘If VMware can actually come out with a decent implementation of PC-over-IP’-like comments.

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

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.