Citrix/Terminal Services/Remote Desktop Services Archives • Helge Klein

Leaked Token Handles Preventing RDS Session ID Reuse

A recent article on Microsoft’s Ask the Directory Services Team blog piqued my interest. It talks about how leaked access tokens prevent logon sessions to be freed when the user logs off. This wastes system resources that can only be reclaimed by rebooting. A symptom of this happening is that RDS session IDs are not […]

VMware Horizon in a Lab: Getting Rid of SSL Errors

This is a description of a quick and dirty way to get SSL to work correctly in a VMware Horizon View installation in a lab environment. Do not do this in production!

Citrix Synergy 2016 Call for Topics: Get Rid of the Video Requirement (Open Letter)

It smacks of lazy reviewers looking for eye-candy. Simon Crosby, former Citrix CTO Citrix Synergy Team, I am writing to you as a guy who has presented many times at Synergy. This year alone I had three sessions, one in cooperation with my community peers Aaron Parker and Shawn Bass, the other two on my […]

Citrix XenApp/XenDesktop API Hooking Explained

What is API Hooking? API hooking is all about making others do things they never even knew they could do. More precisely: tricking other processes into doing things differently from what their developers programmed.

Citrix Desktop Viewer Screen Resolution and Window Size

As far as I know there is no “official” way to set the width, height and screen position of Citrix Desktop Viewer in window mode. It can be done easily by changing a few registry values, though.

Citrix XenApp 7.6 Logon Slow – Long Black Screen Phase

Update 2015-04-28: Citrix provides the limited release hotfix ICATS760WX64009 that fixes this issue. More information below. During the research for my session about the XenApp 7.6 logon process, to be presented at Citrix Synergy and BriForum London, I noticed that the logon to my XenApp 7.6 lab server was taking a bit long. Longer, in […]

XenDesktop 7.6 VDA CPU & Memory Footprint

If you install the Citrix XenDesktop 7.6 Virtual Desktop Agent (VDA) on a small Windows 7 VM, you may be in for a big surprise, and not a good one. This article documents issues I have experienced and how to work around them.

Which Version of Citrix GoToMeeting Are You Running?

Last updated: 2017-01-21. This article still applies to the latest versions of GoToMeeting. The high disk space usage has not been solved yet. Am I running the latest version of GoToMeeting? Which is the latest version, anyway? Those trivial questions might not be easy to answer.

Is my App Running on Citrix XenDesktop/XenApp?

How do you programmatically determine if an application is running in a session accessed over a remoting protocol (i.e. ICA aka HDX or RDP)? It may be Citrix’ strategy to completely hide the fact that a session is remoted – which makes sense in many ways – but in some cases developers simply need to […]

Citrix ShareFile Sync on a New Computer with Existing Data

Switching over to a new computer is certainly fun for a geek, but getting back to a perfectly tuned configuration can be a lot of work, whether you synchronize (part of) your data to the cloud or not.

Solved: Citrix Desktop Service Fails to Start, Logs Event 1006

I am sure you all love XenDesktop VDAs that just won’t register. Although this is becoming less and less of a problem I had another case recently.

Configuring Citrix ShareFile Sync from PowerShell

When you have a cloud-based file sharing service it makes a lot of sense to synchronize part or all of the data with your desktop computer. Citrix ShareFile offers the Sync for Windows tool for that purpose. However, once you open its configuration screen you notice that has a severe restriction: it can only synchronize […]

Persistent VDI in the Real World – Sizing

This is the third article in a multi-part series about building and maintaining an inexpensive scalable platform for VDI in enterprise environments. Previously in this Series In the last article I explained that shared storage should be avoided, for two reasons: it is (very) expensive, and you, the VDI guy, are not in control. The […]

Persistent VDI in the Real World – Storage

This is the second article in a multi-part series about building and maintaining an inexpensive scalable platform for VDI in enterprise environments. Previously in this Series I started this series by defining requirements. Without proper requirements, everything else is moot. Remember that we are looking at running typical enterprise desktop workloads, we are trying to […]

Persistent VDI in the Real World – Architecture

This is the first article in a multi-part series about building and maintaining an inexpensive scalable platform for VDI in enterprise environments. Requirements Before we can even start to think about a possible architecture, we need requirements. Only requirements enable us to make choices that benefit the customer. Without proper requirements we are not building […]

Shutting Down Unused Persistent XenDesktop VMs

When you use XenDesktop the only way it makes sense you may find that Citrix has not really put much effort into making that a smooth experience.

Script: Gracefully Shut Down all VMs on a Given Set of Hosts (VMware/XenDesktop)

Cleanly shutting down all virtual machines on a given set of hosts is not as trivial as it might seem – especially if you want to be able to restore the original state once the planned maintenance you are doing this for is completed.

How WinPE 4.0 Breaks ICA Connections

I had to troubleshoot a case where it suddenly was not possible any more to connect via ICA/HDX to freshly installed Windows 7 VDI machines. As it turned out, the root cause was a combination of Microsoft disabling legacy technologies and Citrix relying on them.

Contest: Why Is This Desktop Empty?

I just had a situation where I was facing an empty desktop with no way to logoff, start a program or do anything else. The only thing left to do was to log the session off from an admin session. This got me thinking: how many ways are there to create such a situation? I […]

How-to: XenApp/RDS Sizing and Capacity Planning with uberAgent for Splunk

Do you know the maximum number of users each of your terminal servers can host with acceptable performance? You may have found out the hard way how many are too many – but how many are just right? Farm sizing and server capacity planning are typical tasks for consultants who often have a hard time […]

Comparing the CPU Performance of Physical and Virtual PCs (VDI)

When you move users from a physical PC to a VDI environment you may find that they are not too happy with their new machine’s performance – it happened to me. To quantify things I took a series of measurements comparing the old PCs we migrated away from with both VDI machines and the new […]

The Effects of HP’s Power Profile on vCPU Performance

When you buy a new HP server it comes with the BIOS setting HP Power Profile set to Balanced Power and Performance. That sounds good but is bad – at least for CPU performance in a VDI environment.

Getting USB Smart Card Readers to Work with Citrix XenDesktop

Even if you only have a moderately sized VDI deployment chances are high you will face the problem of getting USB smart card readers to work on the virtual desktops. Given that this is such a basic requirement it is astonishingly hard to implement correctly. To save you the pain of having to start from […]

XenDesktop Logon Failure: Desktop Viewer Pops up and Closes

Know this problem? You try to start a XenDesktop session, Desktop Viewer opens … and closes. Then nothing.

XenApp and RDS Sizing Part 4 – Calculating the New Farm’s Capacity

This article is part of a mini-series. You can find the other articles here. In the previous articles in this series we saw how to calculate a farm’s capacity and then how to determine its load. With that information and knowledge of our methodology we can go about calculating the capacity of the new farm, […]

Batch Delete Issued Citrix User/Device Licenses with Udadmin

Udamin.exe is a handy tool for managing Citrix user/device licenses. To get a list of currently issued licenses run it like this: C:\Program Files\Citrix\Licensing\LS>udadmin.exe -list Usage data is 15 minutes old. Next update in 1 minutes. Users: username1 XDT_PLT_UD 2013.0815 username2 XDT_PLT_UD 2013.0815 Devices: computername1 XDT_PLT_UD 2013.0815 computername2 XDT_PLT_UD 2013.0815 You can delete individual license […]

XenApp and RDS Sizing Part 3 – Determining Farm Load

This article is part of a mini-series. You can find the other articles here. In the previous part of this series we saw how to determine the capacity of a server farm. This time we will look at how that capacity is utilized, in other words at farm load. As before we will do that […]

XenApp and RDS Sizing Part 2 – Determining Farm Capacity

This article is part of a mini-series. You can find the other articles here. As we have seen in part 1 of this series, when sizing a new farm the first thing we need to know is the capacity of the existing farm. Armed with data on capacity and additionally load, we can easily calculate […]

XenApp and RDS Sizing Part 1 – Methodology

This article is part of a mini-series. You can find the other articles here. One of the first things you need to do after starting a XenApp farm upgrade project is to answer the obvious question from management: how much will it cost? In order to be able to answer, you need to have a […]

Do Shadow Keys Still Work in Server 2008 R2?

Shadow keys have been around forever, since way before Terminal Services were renamed to Remote Desktop Services (does anybody use that name?). It seemed they would stay in the OS forever, too. Yet, when installing applications on Server 2008 R2 many people notice that the shadow key area does not get populated. Let us find […]

Category: Citrix/Terminal Services/Remote Desktop Services

Leaked Token Handles Preventing RDS Session ID Reuse

VMware Horizon in a Lab: Getting Rid of SSL Errors

Citrix Synergy 2016 Call for Topics: Get Rid of the Video Requirement (Open Letter)

Citrix XenApp/XenDesktop API Hooking Explained

Citrix Desktop Viewer Screen Resolution and Window Size

Citrix XenApp 7.6 Logon Slow – Long Black Screen Phase

XenDesktop 7.6 VDA CPU & Memory Footprint

Which Version of Citrix GoToMeeting Are You Running?

Is my App Running on Citrix XenDesktop/XenApp?

Citrix ShareFile Sync on a New Computer with Existing Data

Solved: Citrix Desktop Service Fails to Start, Logs Event 1006

Configuring Citrix ShareFile Sync from PowerShell

Persistent VDI in the Real World – Sizing

Persistent VDI in the Real World – Storage

Persistent VDI in the Real World – Architecture

Shutting Down Unused Persistent XenDesktop VMs

Script: Gracefully Shut Down all VMs on a Given Set of Hosts (VMware/XenDesktop)

How WinPE 4.0 Breaks ICA Connections

Contest: Why Is This Desktop Empty?

How-to: XenApp/RDS Sizing and Capacity Planning with uberAgent for Splunk

Comparing the CPU Performance of Physical and Virtual PCs (VDI)

The Effects of HP’s Power Profile on vCPU Performance

Getting USB Smart Card Readers to Work with Citrix XenDesktop

XenDesktop Logon Failure: Desktop Viewer Pops up and Closes

XenApp and RDS Sizing Part 4 – Calculating the New Farm’s Capacity

Batch Delete Issued Citrix User/Device Licenses with Udadmin

XenApp and RDS Sizing Part 3 – Determining Farm Load

XenApp and RDS Sizing Part 2 – Determining Farm Capacity

XenApp and RDS Sizing Part 1 – Methodology

Do Shadow Keys Still Work in Server 2008 R2?