I spent most of the week before last at Synergy in Houston, co-presenting a breakout session on XenDesktop architecture, and in a number of customer and partner meetings. Most of the time, however, I demo-ed XenDesktop to the public in the technology lab - or at least, that was the plan.

In reality, a lot of the time I actually ended up using pen and paper to sketch out XenDesktop, and how the various components that make up this product work together to deliver an end-to-end desktop virtualization story. Once the basic ideas behind XenDesktop got across, it was a lot easier to walk through the UI and demo the product. The other Citrites at the XenDesktop booths had exactly the same experience of typically setting up the scene before delving into details.

So I thought I'd try recording what I did in Houston as a little video - it's a bit rough round the edges, and it doesn't cover the full gamut of what XenDesktop can do (it doesn't talk about how you can assign individual virtual desktops to users, for instance), but it'll help explain some of the principles and ideas behind XenDesktop, and perhaps also shows where and how it differs from other VDI solutions.

PS: Sorry for my handwriting - it's never been very good...
PPS: XenDesktop (including the free Express edition) is now available for download from mycitrix.com

I'm not sure where or when this conversation took place, but PC World had an interview with Simon Crosby, the CTO of the Virtualization and Management Division at Citrix, about future plans to build on Hyper-V. It was an interesting read, and I think that it helps reinforce a point of view in that no one company is going to have a hold on the virtualization market, it is going to have to be about interoperability, as we have only just begun to mold whatever form this market may become.

Continue at Source: Citrix CTO Mum on Plans to Build on Microsoft's Hyper-V

Streaming Client 1.0 was the original release of the client that accompanied Presentation Server 4.5.

Streaming Client 1.1 shipped with PS 4.5 HRP1, around September 2007.  It included some performance enhancements that are not widely understood.  This blog post brings a bit of attention to some good work.  Under the hood work, but still good work.  The upcoming Delaware release will include additional performance enhancements. 

The Streaming Profiler has a few jobs.  The primary one is to "observe" the actions of an installation program, prevent the installation items from really occurring and "write down" what the installer tried to do to the machine.  This writing down part includes two primary items, the "file system" and the "registry".

If you peek inside an application streaming profile, you will see a ".profile" file.  This is the highest level file.  It is XML formatted data that describes everything needed for publishing.   There are a series of "CAB files" that hold the execution content for 1 or more execution platforms.  These "CAB files" are the backing store that support execution.  They are often called "execution targets" and they store the registry content and disk content for actually running the program.

The registry data is inside a .TAB file and isn't important for today's conversation.  The disk content is stored below the \Device folder in the CAB file and holds everything that was "installed" to the file system - potentially, lots of stuff.

Now - why did we use CAB files to hold this?

Is an excellent question and one of great debate in the development circles.  Instead of a compressed CAB, the content could just as easily be a directory with everything stored below that directory.  The CAB was used to faciliate offline access and make it a boolean decision on "its there" or "its not there".  Looking back, this was doable without a CAB, but we have what we have right now.  

The trick!  Efficient access to CABs.  Accessing files inside a CAB is not as efficient as accessing files beneath sub-directories. 

When creating an isolation sandbox, the streaming and isolation system needs to "know" what was stored during profiling.  When an application at runtime does a "DIR", the response to that directory enumeration uses information that "isn't there".  The information is provided to the application based on what "was there" at profiling time rather than was "is there" at runtime.  If the application then opens a file that isn't there, the streaming system makes the file "present" before completing the file operation.  This last item is a "cache fill" and is the basis of the "streaming" part of Application Streaming.

Consider: How do you construct a list of all the files in the CAB?

In the Streaming Client 1.0, this list was constructed as a part of creating the isolation sandbox.  That is, created at runtime.

it was assumed that an administrator might update the CAB file "behind the back" of the Streaming Profiler.  With this, the contents of the CAB were scanned at application launch and the directory structure for enumeration was built in memory based on the scan.  Hindsight says that this was a BRUTAL activity for performance.   Actually, it only was a problem for "large" applications, but here it was a real concern.   The problem is that it happens EVERY launch, not just first time launch, so this makes the inefficiency a big thing to be concerned about.  It was a big enough concern that we "fixed it" in 1.1.

In Streaming Client 1.1 (4.5 HRP1), the Streaming Profiler was enhanced to store the directory enumeration data as part of saving the profile (target).  With this data available in a single place, the Streaming Client could "skip" the DIR /S on the CAB file and speed application launch -- Greatly faster!  A side note is that the admin can no longer update the CAB file behind the back of the Streaming Profiler.  No worries, nobody was doing that anyway.

To get the benefit of the meta-data stored with the execution target, the existing profile needs to be loaded into a 1.1 level Streaming Profiler, the Target needs to be edited and then saved.  Done.  The 1.1 Streaming Client looks for the meta-data.  If its there, it uses it.  A 1.0 level Streaming Client will access the files of the CAB "the old way" and this makes the profiles backward and forward compatible even with the change.  Computer Science is fun stuff!

What's the future... 

In Streaming Client 1.2, this is taken a step further to change the compression of the CABs in a manner that's more friendly with WanScaler and happens to give a great benefit to first time launch performance.  I'll save that for a later blog entry, probably "post-Delaware".  For now, you should know that the CAB file in 1.0 and 1.1 is created in a format that allows more efficient single file extracts than does the default formatting from CABARC or similar tools.

In a dream, I'll shoot CAB files completely.  Truth is, won't get there anytime soon.

Joe Nord

Product Architect Application Streaming, Citrix Systems Fort Lauderdale, FL 

Can the Delaware level Application Streaming client be used with PS 4.5 level servers? 

Quick answer: Yes.

Long answer:...I get this question alot.  So much so that this blog will serve a useful reference so I don't have to type the same information over and over.  Part of this is my own fault, having just returned from Citrix Synergy conference where the first question I received AFTER the App Streaming breakout was: Can I use the IIC enabled Streaming Client on PS 4.5 servers?  Argh!  How did I forget to mention that to the room full of hundreds of people?

"Delaware" is Citrix codename for the Presentation Server release targeting Windows Server 2008 as an execution platform.  The Delaware level Streaming Client is the one that will have Inter-Isolation Communication (IIC) and HTTP based streaming, so its a hot item.   The Delaware level Streaming Client is better described as Streaming Client 1.2. 

Since Delaware is specific to Server 2008, the question is really one to say: Do I have to go to Server 2008 to get IIC? 

Answer: No.  You can install the 1.2 Streaming Client on PS 4.5 servers and you get the 1.2 level function on the older PS platform.

Streaming Profiler/Client - Version history 

• 1.0 Presentation Server 4.5 GA
• 1.1 Presentation Server 4.5 HPR1
• 1.2 Delaware (not yet released...)

Hey Joe: IIC is pretty compelling stuff, why isn't the version number 2.0?  Answer: There's no good reason.  2 was bigger than 1 and it makes the numbers different, so that's all we did.  I'm not a huge fan of bumping version numbers just for entertainment.   I have a long history of major.minor changes causing troubles, so I tend to just bump one of the numbers.

The 1.2 Streaming Client can be installed separately from the server (Stream to client).  This concept is easy. 

The 1.2 Streaming Client CAN also be installed on top of PS 4.5 HRP1 Servers (32 and 64 bit). 
This will bring 1.2 streaming client function to PS 4.5 servers!  This is important.

More important: Yes, we intend it to work that way.  Yes, we are even testing it and YES, it works!

The Streaming Client is a client.  Think "ICA Client".  The client does not REQUIRE a Presentation Server release for the client to be updated.  So far, we've shipped the streaming client only when using the ship vehicle of the Presentation Server; but this isn't required.  Also consider that ICA Client can be installed on top of Presentation Servers - enabling pass through.  The same concept applies to Streaming Client. 

What about the data??  (profiles) 

Profiles created with Streaming Profiler 1.0 and Streaming Profiler 1.1 CAN be used with the 1.2 Streaming Client.  This "forward compatibility" works as would be expected.  Performance enhancements were added in 1.1 and additional enhancements added in 1.2 so there is value in "updating them".  But, if 1.0/1.1 profilers are in the field and working the cost of doing the update is probably bigger than the value of the performance boost so this alone isn't a big enough reason to go update everything. 

"Older profiles" can also be Inter-Isolation Communication enabled via IIC function of Streaming Profiler 1.2 with no need to reprofile the existing applications.  That is, 1.0, 1.1 created profiles can participate in IIC - which is pretty cool!

Going backwards, it gets trickier: Streaming Profiler 1.2 created profiles that do not use IIC *CAN* be consumed by the 1.1 Streaming Client.  This is conceptually, forward compatibility, but forward compatibility has limits.  A 1.1 level Streaming Client has no idea what is "IIC", so it cannot consume an IIC enabled profile created by the 1.2 Streaming Profiler.   Well, technically it can consume it enough to figure out that it can't handle it.

Where a streaming client (old) "lacks" capabilities to run applications from a profile (e.g. IIC), the old streaming clients include a polite error message to describe this and recommend an upgrade to a newer streaming client.  This has existed from the beginning (1.0) and will only now be exercised in 1.2 and only where IIC is enabled.  Generally it doesn't come up because admins upgrade the clients, but its there none the less. 

Update: After writing this, one of the streaming developers commented that the HRP1 level AMC will not understand an IIC enabled Streaming Profile.  True.  Solution: Use Delaware level AMC to publish into 4.5 farm.  Hopefully that works.

Joe Nord
Product Architect Application Streaming, Citrix Systems Fort Lauderdale, FL

In a previous series of articles I gave you look at the Partner Tech Preview of Citrix Workflow Studio, which was only available to Citrix Partners. I am very excited to announce that the release of the Community Tech Preview of Citrix Workflow Studio should be available everyone very soon! So while we wait for it to be released, I am going to highlight what has been added to the Citrix Workflow Studio Community Tech Preview that was not in the Partner Tech Preview. Also, I would like people to understand that a Tech Preview is a working product, but by no means is it the final product; it's the feedback from the community that will help make it a product we all will want it to be, which is why it is a preview and not a demo or a beta.


You can view the individual Citrix Workflow Studio Partner Tech Preview articles from the below links:

Citrix Workflow Studio - Preview Part 1
Citrix Workflow Studio - Preview Part 2
Citrix Workflow Studio - Preview Part 3
Citrix Workflow Studio - Preview Part 4
Citrix Workflow Studio - Preview Part 5
Citrix Workflow Studio - Preview Part 6


You can download the complete Citrix Workflow Studio Partner Tech Preview from the below link:


Introducing Citrix Workflow Studio - The Complete Introduction


You can download the Overview of the Citrix Workflow Studio 1.0 Community Tech Preview from the below link



Continue to Download: Citrix Workflow Studio 1.0 Community Tech Preview - A Quick Overview

Citrix is pleased to announce the availability of Workflow Studio 1.0 Tech Preview which is our Community Technology Preview for the product.
You can download the product from the below link once you have a My Citrix account (Which you should. It only takes a minute. We promise.)

Continue to Download: Citrix Workflow Studio 1.0 Tech Preview

In addition to the scheduled sessions for the 23rd and 24th,

http://xen.org/files/xensummitagenda.pdf

they have added a NEW! track to be held on the 22nd

http://www.usenix.org/events/usenix08/training/tutonefile.html#s4

Introduction to the Open Source Xen Hypervisor

Todd Deshane and Patrick F. Wilbur, Clarkson University; Stephen Spector, Citrix

Who should attend:

System administrators and architects who are interested in deploying the open source Xen hypervisor in a production environment. No prior experience with Xen is required; however, a basic knowledge of Linux is helpful.

The Xen hypervisor offers a powerful, efficient, and secure feature set for virtualization of x86, x86_64, IA64, PowerPC, and other CPU architectures, and has been used to virtualize a wide range of guest operating systems, including Windows, Linux, Solaris, and various versions of the BSD operating systems. It is widely regarded as a strategically compelling alternative to proprietary virtualization platforms and hypervisors for x86 and IA64 platforms.

Take back to work:

How to build and deploy the Xen hypervisor.

Topics include:

• Xen architecture overview
• Building a Xen hypervisor from Xen.org
• Installation and configuration
• Virtual machine creation and operation
• Performance: tools and methodology
• Best practices using Xen

Continue to Xen Summit: http://xen.org/xensummit/

I was fortunate enough to recently meet Christian Knermann from the Fraunhofer Umsicht Institute in Germany. Christian and some of his colleagues conducted a study on the positive environmental impact of replacing PCs with thin clients, using XenApp to deliver their desktops and applications. Having very precise  calculations combined with a detailed explanation of how these calculations were made is significant.

I've been promoting the concept of Green IT within and outside of Citrix for some time now,  motivated by the desire to do something for this world we live in at work as well as in my personal life. While I haven't converted to solar power yet, I have replaced all my commuting and most of my personal traveling from car to bike. I know this isn't something everyone can do (and I can't lug my family of 5 behind me on a bike), I believe we all can do something to reduce the environmental impact of IT operations.

I won't get into the argument of the causes or even the existence of global warming, but it is obvious to anyone that the more electricity we use to power Data Centers and end-points, the more pollution is released into the air. As well, the frequency in which we replace our hardware (and I have been a culprit here) in turn increases the amount of landfill, including some hazardous materials, into the environment.

In my efforts to raise Green IT awareness, I have seen a lot of calculations of the benefits of one technology over another. Sometimes its difficult to verify or even understand the math involved - which has been noticed and noted by others. Particularly when these calculations are on the power consumed or saved, and the costs involved. In many of the cases, I can see the logic behind them and therefore give the results some credence, but I would not have the same level of confidence if I had to relay these figures to an audience, especially one comprised of geeks who tend to, like me, question figures that are stated.

And that is where the Fraunhofer study becomes useful. Their study takes into consideration criteria such as the entire life-cycle of hardware from manufacturing to disposal, the different profiles of user from light to power users and even the effect of powering off at night. Impact was measured not only in power consumption, but also emissions, hazardous waste and even water consumed. The report is very detailed and includes a lot of graphs and tables to support their findings.

I recommend that anyone interested in implementing Green IT take a look at the report which can be found here. While the primary focus of the report is on replacing PCs with Thin Clients, it also covers in summary additional approaches such using 64 bit processors as well as virtualization.

If you speak german, you can also see and hear Christian talk about his work at the Synergy Underground site(http://community.citrix.com/underground/). The badly mangled german questions are from me .

Introducing RepairCBDChain a Citrix Tool written by Dmitry Vostokov,
a tool that immediately restores clipboard functionality on the client and server.

Have you ever had a problem where the cut and paste clipboard functionality would not work in a ICA session? I know, silly question, of course you have. I would like to introduce you to a tool I use whenever the clipboard functionality stops working. This tool was written by Dmitry Vostokov a Citrix employee in EMEA. I had the pleasure of meeting him while I was over in Dublin, Ireland visiting the Citrix office there. He is an amazing individual with many accomplishments, you should seriously check out his site, Crash Dump Analysis. http://www.dumpanalysis.org/, I'm willing to bet that you will be as awed as I was.

Continue to download RepairCBDChain:

http://support.citrix.com/article/CTX106226 (32-bit)
http://support.citrix.com/article/CTX109234 (64-bit)

Here is a quick snippet from a session that Dmitry Vostokov gave at PubForum 2008 in Dublin this year.
(PS - You may have to turn up the audio to hear it better)

?

Continue to PubForum for the full video and powerpoint:

http://www.pubforum.info/welcome/PFResources/tabid/55/Default.aspx
http://www.pubforum.info/welcome/Portals/0/PubForums/DUB08/PPT/Hyper-V.ppt
http://www.pubforum.org/videos/DUB08/Citrix_Tools.wmv

I have been blown away by the great response we got to our first ever Geek Speak Live event at Synergy. From the speakers who were willing to get up in front of a 500+ crowd and be controversial and confronting, to those in the 500+ crowd who asked thoughtful and sometimes confronting questions, and to those who came up to me during breakfast with support and encouragement and ideas. Rather than spend too much time reviewing what was said during the event (which you can view here on Synergy Underground - look for the "Geek Speak" section), I'd like to hear feedback from both those who attended as well as anyone who has seen the videos on what we would like to do next.

Untill we can host another Geek Speak at the next Citrix event,  we could run a regular series of webinars where once again the topic could be anything technical. Speakers could come from Citrix, our CTPs, other IT bloggers/commentators or any of you out there in the community. Another (additional) option is that both the sessions and questions/comments could be via pre-recorded video, allowing anyone in any time-zone to participate. We will also be using our new ADI Forums to keep the discussions going for how ever long people are interested in them (or they stay technically relevant ).

As we work out the next steps, I'd appreciate any comments and suggestions you may have by commenting to this blog or, even better, posting them to the forum at http://forums.citrix.com/thread.jspa?threadID=150000&tstart=0.

Synergy 2008 was a great event, and I wanted to introduce you to a group of people, among the many other people, who have done their part in making all the magic happen at Synergy. They have been the crew year after year that have made all of our events possible. Missing this year was Donnie Page, but he had the best excuse, something about his wife having a child or something, congratulations to you and your family, which now includes a new baby girl, we missed you. I was in awe at how organized this team was and how quickly they went about getting everything setup, not to mention the long hours. Thank you all for the great job well done, and please help me add anyone to the list that I may have missed, you guys rock!

Brian Miller
Fabian Wright
Doug DeLucca
Greg Sanders
Ray Stanton
Jesse Lazcano
Riley Cooper
Chris Schultz
Mike Delaguardia
Brian Moss
Mike Rossi
Mike Morris
Cory Ohm
Kpayah Tamba
Allen Furmanski
Pedro Llugano
Jose Rios
David Moxey

Here are a couple of photos I took during a well deserved night out for dinner:

Synergy 2008 turned out to be an incredible event, it was an Expo, an iForum, IT 2.0 , and it was Geek Speak Live all in one. I had my reservations at first, as I really didn't like the idea of moving it from October to May, which in my point of view, put it in the same time slot as so many other events. I knew that this had the possibility of making people having to choose which event to go to during this time. I would like to thank all of you that were able to attend, and I hope that it was all that you expected and more.

Here are some photos I took during the first day registration:

Citrix has grown its position in the industry and in the community, we hope to hear from you, as we would like to know how we can make things even better, please let us how we can make Citrix and our involvement go to places never thought possible.

Thanks for attending and we hope to see you next year!

On behalf of the Synergy Underground team, we would like to thank you all for tuning in and watching.
We hope that we have given you a uncensored glimpse into the goings on at a Citrix Event,
and what better event to kick it off with other than at this years Synergy!

Please say hello to the Synergy Underground team:

John Fanelli
James Rabey
Chris Fleck
Barry Flanagan
Vishal Ganerwiala
Adam Marano
Sunil Kumar
Gus Pinto
Rich Crusco

We would like to take this Underground idea to the next level, so please feel free to let us know what we can do to make it even better. What did you like, what didn't you like, what should we have done, what shouldn't we have done, or just what ever you think.

Thanks again and stay tuned for more!

Continue to the synergy underground:
http://community.citrix.com/underground/

It was great to see all of the many people that came to Geek Speek Live, and it was even more incredible to see that it turned out to be a standing room only event! Not that I didn't want everyont to have a seat, of which we apologize to you for underestimating the amount of people who would be attending. We knew that there was a need and demand for people to have a voice and dialog with Citrix community, but who would have guessed that it was going to be this big

Here are some photos I took on day 1 of Geek Speak Live

I want to thank everyone who was involved in Geek Speak Live, the people who envisioned it, the people who helped make it a reality, the people who set it up, the speakers, the sponser (Intel), and of course the attendees.

We look forward to any and all feedback you have to making this and even more impressive event, so please, if you have any ideas or feedback please let us know how we can make it even better.

Thank You All!

Why coffee break?  During logon time?  Our logon time is good, no issues there, and so on.  How many of you faced this situation at customers?  We assume quite a bit.  During all the years working at XenApp projects and recently started with XenDesktop projects at several customers, everyone probably faced that logon times are not usually the best.  Users get used to it and do not complain anymore, so there is no issue, because everyone has a coffee break!
Taking the latest announcement of Citrix about the acquisition of sepago's user profile solution shows again that there are still challenges out there requiring a solution for a stable user profile environment.

Asking administrators about their biggest challenges in a centrally delivered desktop environment, they will usually respond with either "printing" or "user profiles" related to logon and logoff process.  Exactly at this point, many administrators are not familiar with the executed background processes during logon and logoff, which makes troubleshooting difficult for further optimization.

Taking this into consideration, the logon process is usually the first impression an end-user will experience logging on to a centrally delivered desktop, which can be either a XenApp server or a virtualized desktop through XenDesktop.  If this process takes too long, the user acceptance will drastically suffer and leading to the fact that people start questioning a centrally hosted desktop or application infrastructure.

How is the logon process of a user? Roughly the following happens during logon:

1. The user launches a published application (XenApp) or published desktop (XenApp or XenDesktop)
2. Citrix component related processes such as load balancing or assigning a virtual desktop or verification of Microsoft TSCAL (XenApp)
3. Authentication of user at domain
4. Copy of user profile
5. Application of group policies
6. Execution of other processes such as logon scripts
7. Citrix specific processes such as mapping of client devices or printers
8. User access published application or published desktop

You may ask now, why is the logon process not detailed more granular? The answer is pretty simple: The logon details are too complex for XenApp or XenDesktop to be listed in this blog.  A good source to get an overview of what is happening during logon and logoff is at Brian Madden's website, which provides a flow diagram that can easily fill out a A3 format printout.

Now, knowing what is happening roughly, how can I diagnose my logon process?

A good starting point is to leverage Microsoft's built-in tool for logging all Windows processes during logon - the "User Environment Debugging".  This is by default disabled and can be enabled by adding a registry key, which is described Microsoft's Knowledge Base article 221833.

Another good tool is the usage of Citrix EdgeSight, where administrators have the option to isolate performance related issues since EdgeSight provides a user-centric view of delivered applications and desktops.  Furthermore, administrators can also leverage tools such as Windows Performance Monitor, Windows Systinternal Regmon and Filemon or other command line tools.

However, let's have a look at typical suspects for issues and the according screws to be used.

• Domain Controller.  This is the core of any Active Directory and the main component during the user logon process.  We could discuss this component in details filling an entire book; however want to highlight only a few relevant screws.
  • Ensure sufficient system resources
  • Properly running DNS (primary name resolution of Windows Server 2003)
  • Monitor your domain controller - especially during peak logon times

      All of the above components have an impact on the logon process, therefore, know what is happening there.

• User Profiles & GPOs.  User profiles provide a user their "personalized" environment depending on the user profile strategy, which again has a huge impact on logon times.
  • Roaming Profiles provide maximum personalization such as nice wallpapers, saving files on the desktop (especially large files), etc., however can also get quickly out of control if not restricted by certain policies.  Therefore, it is crucial to define a user profile strategy first before starting with any optimization.
  • An ideal profile solution is a Mandatory Profile customized by an administrator that does not allow any personalization by users since it discards any changes applied during runtime.  This is a stable solution however this will probably not meet all users' expectations.
  • A hybrid solution provided by Citrix User Profile Manager, which is based on the recently acquired technology from sepago called sepagoPROFILE.  The biggest advantage of this solution is that users gain a certain degree of personalization (pre-defined by an administrator) while keeping the stability and slimness of a mandatory profile that ensures a fast logon process.  Other similar solutions are provided by partners such as AppSense, RES, and tricerat.
  • Placement of user profiles may also affect the logon process since any additional network hop, procedures to locate the file server (e.g. DNS) as well the file servers' utilization can delay logon times.  A possible improvement with mandatory profiles is storing them locally on a XenApp to avoid network copy jobs.
• Group Policies.  Provide administrators a way to control an Active Directory-based environment.  However, they should be used carefully by reducing it to a minimum set of required group policies, because each policy needs to be processed during logon extending again the logon time.  Thereby, the amount of configured settings is more relevant than the amount of group policy objects.  In order to ensure fast logon times, consider the following:
  • Do not configure unnecessary settings
  • Disable not required settings (e.g. applying solely user specific settings does not require the processing of computer specific settings)
  • Import only required ADM files

Once group policies have been created, you should analyze these with the tool GPResult or RSoP to check for duplicate or conflicting settings.

• Anti-Virus software.  Today, there is almost no XenApp or XenDesktop environment without Anti-Virus software.  Taking this into account, usually the default configuration is applied, which may be not appropriate and can lead to a delayed logon process.  Therefore, the following configuration settings are recommended:
  • Scan on Write only
  • Scan only local drives
  • Exclusion of .DAT files

Another performance enhancement can be achieved if an organization's security guidelines permit to scan only files with executable code.  Further details can be found in article CTX114522.

•  Other possible areas.  Besides the above listed areas and others not covered in this blog, the following are relevant as well:
  • Mapping of client resources such as printers, local drives, audio, COM or LPT-Port - usually the user has access to its desktop once these have been mapped
  • Number of concurrent logons - the amount of executed processes create load on the Write process to the hard disk such as copying user profiles, mapping client resources etc and can be addressed with faster hard disks or a RAID-Controller with a battery backed-up Read/Write Cache.

Even if user profiles provide the impression of a less complex component of the logon process, they should be considered as part of the architectural planning of a XenApp or a XenDesktop environment since every "cool" function may also lead to a delay in logon times.  Doing so, this will ensure acceptable logon times (with no coffee breaks improving efficiency), happy users, less help desk calls because of corrupted user profiles, and cost savings.

We hope that the discussed tools and techniques give you more insights into the logon process.  Luckily, we have now a tool that we can leverage to use in order to ensure happy users.  Therefore, we can only encourage to test out the Citrix User Profile Manager!

Note:  This content was created by Thomas Berger and Tarkan Koçoglu (both from Citrix Consulting) and has been already published in the German Magazine LANline, Edition April 2008 and the Citrix Newsletter "iPunkt Edition 38, April 2008"

Being a Sr. Architect within Citrix for almost a decade, I've been asked by more Citrix administrators than I could ever count, wanting to know if they should virtualize their XenApp environment.  My typical response, which is common for a consultant, was "It depends."   Unfortunately, this is not an easy yes or no question.  XenApp is a unique beast in the delivery center.  Users don't interact indirectly with a XenApp server like they do other systems (database, web, etc). Instead, users work on the servers directly.  And if the servers have been designed appropriately, they should reach their memory limit or CPU limit.

Let's say, for example, your business is to write screenplays for "The Simpsons" and you have a set of XenApp servers hosting a single application for storyboarding.  This application is critical to the business.  On average, throughout the day, the CPU is 60% utilized and the memory is 80% utilized (4GB on Windows 2003 Server).  What advantage would you gain by virtualizing this system?  The hypervisor WILL take resources.  Chances are slim you would be able to host a second virtual server on this physical system.  In this case, I don't see where server virtualization fits. You could add more memory and additional CPU sockets, but you are spending more money just to try to save money.  Of course there are some XenApp servers that are underutilized.  Why?  Was it an improper design? Or was there a business reason? With underutilized severs, we do have the opportunity to reduce the XenApp hardware footprint somewhat.  But in my opinion, server virtualization is trying to solve a small problem in the XenApp world, consolidation.  With proper hardware design, this can be mitigated. I have seen, based on my experience as a consultant and an administrator, the bigger challenge is management, availability and flexibility. 

When I was an admin, we used to have a scripted build for our MetaFrame 1.0, 1.8 and XP servers.  The scripts were very elegant and worked like a champ (I can say this because I wrote them), but they were a pain to maintain.  Plus you had to take into account hardware changes, application modifications, etc.  I've seen people go to cloning-like solutions, but you still have hardware configuration challenges, which I've seen some people end up with 10, 20 or even 50 different images.  When it was time to patch those systems, the good times rolled (sarcasm). Server virtualization cloning has the same challenges, although hardware changes are mitigated by the hypervisor.  Cloning in the virtualization world allows one to quickly get a system up and running, but does little for maintaining the images.  Just in my own personal lab, I've got roughly 20 virtual images.  And it seems like every time I turn on one virtual machine, there are new updates!!!  We have all heard of DLL-hell, well new we have Patch-hell. 

And we all love the server virtualization solution, even I do, which is why I'm writing this blog entry instead of preparing for my Synergy sessions or watching a good episode of The Simpsons without my boss catching me (Hope he doesn't read these). Everyone is talking about it as the next big thing, but we will continue to have tons of servers that are not virtualzed.  Does that mean 2 solutions, 2 sets of images, 2 sets of tools based on your environment?  When I think of that, I'm thankful I'm not an administrator. But this is where the story gets really interesting:

Provisioning Server integrated with XenServer, what a great concept.  One image for multiple servers.  And what's more, that one image can span virtual and physical servers.    When I need to make an update to the app or OS, I update one image and reboot the servers.  Time to rebuild the farm equals the time it takes to reboot the farm.  I don't care if the server is physical or virtual, they are all the same to me.  As I use this integrated solution more and more, I am impressed with the ease of maintenance.

But let's get back to the original question... If you now ask me if you should use server virtualization integrated with your XenApp environments, my answer has not changed... I will still say It Depends.  But what I say next is to look at the bigger picture.  Why do you want to virtualize? What are you trying to solve? What is wrong with your XenApp environment that you are looking at server virtualization?  And I bet the more we look into it, we will end up with a challenge revolving around management, availability or flexibility.  So I dare you to ask me, but be ready for a longer conversation, which will include some relevant Simpsons quips as well.

If you are interested on architectures, guidelines, implementation guides, then I encourage you to take a look at a set of materialsI've developed focused on the integration of XenServer and XenApp.  If you think I'm totally on, let me know so I can show my boss how awesome I am, but I'm also game for a good discussion with differing viewpoints. 

This whitepaper recently released by out guys in consulting covers the design considerations on how policies can impact your XenApp (Presentation Server) 4.5 environment...

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There are numerous ways to apply a configuration or security setting onto a group of servers within a Citrix Presentation Server environment. Because policies are so unique, diverse and customizable, there is no single, correct method toward policy design. However, this document will give the key areas to consider when deciding on the appropriate approach to implementing a setting using a policy.  
This design consideration will look at the following types of policies and the comm on practices associated with them:

• Citrix Presentation Server policies: These policies are defined within the management console on Presentation Server and only apply to connections using the Citrix ICA protocol but not the Microsoft RDP protocol. Presentation Server policies also allow for the configuration of Presentation Server-specific options like Session Printers and Progressive Display. The power of these policies is that they have the ability to be filtered based on users, location and even the method for launching the published applications. Many of these filters are only available within Presentation Server.
  
  
• Active Directory Policies: These policies are configured within Active Directory. They are applied to organizational units (folders), domains, sites, etc. within the Active Directory structure. A single Active Director y policy can consist of a computer policy and a user policy. A computer policy consists of settings that affect the physical computer and impact all users logging onto the computer while a user policy affects the user and is applied on all systems the user logs on to. Local server policies and custom policies are types of Active Director y policies and are described as:
  
  
  • Local Server Policies and Settings: Local Server policies are similar to Active Directory policies, except they are managed on a server-by-server basis and configured locally on that specific server, where Active Directory policies are managed centrally and can impact hundreds or thousands of users or computers with a single application of a policy.
    
    
  • Custom Active Directory Policy Templates: Custom ADM templates, like the Citrix icaclient.adm template, are Active Directory or Local Server policies used to make configuration settings. They can be custom registry settings or simply standard policies re-organized as two examples. The concept of custom templates is supported, but depending on the author of the custom template, supportability by either Citrix or Microsoft might not be available. Organizations will have to verify the supportability of custom ADM templates. Also, any custom template used might already have settings configured, potentially causing issues with the environment. It is highly recommended to test custom policies in a test environment before implementing in production.

The following five areas are the basis f or the design decisions for an enterprise deployment of Presentation Server. These types of policies will be impacted by the following design areas:

• Policy Type
• Policy Integration
• Policy Filters
• Policy Prioritization
• Policy Precedence
  
  

Download it here

I think this is the most useful post ever for Citrix admins!

Seriously it has always been hard for me to find where and what are the latest hotfixes for the Citrix products... but this picture has changed.

With the new revision of Citrix's Support site (support.citrix.com), now it's easier to find  the latest fixes and patchs for your Citrix products.

Here's the list:

Presentation Server 4.5 for Windows Server 2003 - x86

Presentation Server 4.5 for Windows Server 2003 - x64

Presentation Server 4.0 for Windows Server 2003 - x86

Presentation Server 4.0 for Windows Server 2000 - x86

Access Gateway 4.5 Advanced Edition

Access Gateway 4.5 Standard Edition

Access Gateway 8.0 Enterprise Edition

Provisioning Server 4.5

Citrix NetScaler 8.0

Citrix NetScaler 7.0

Citrix WANScaler 4.x


Select the products you have, subcribe to its RSS feed and stay in-sync with all later patches and fixes for it.
This is wicked useful!

Cheers,
Gus Pinto

I have taken all the posts in the series that I released on the Citrix Workflow Studio Partner Tech Preview, and have incorporated them into a single document.

After receiving many requests from people to make the entire series of articles available as a downloadable document, how could I not make one available.

So here it is by popular demand, enjoy!

Download: Introducing Citrix Workflow Studio - The Complete Introduction
 

This video is a follow-up from my previous one with a bit more information on the app, a greater insight on how it works and how it was built.

Stay tuned as I wil be releasing more information on Citrix Fast Launch on the next few days.


cheers,

Gus Pinto
Technology Evangelist
Microsoft MVP - Virtualization

*PS. Check out the HALO 3 sticker on the back of my notebook.