Dedicated VM shuts down and remains powered off, even though logoff behavior “ShutdownDesktopsAfterUse” is set to false

Dedicated Virtual Machine shuts down and remains powered off, even though Logoff behavior ShutdownDesktopsAfterUse is set to false.

Cause

The problem occurs after updating the master image of a Dedicated type catalog using the PowerShell SDK commands listed under CTX129205 – How to Update the Master Image for Dedicated and Pooled Machine Types using PowerShell SDK Console.

Changes applied to the master image of a Dedicated Catalog should only affect new machines created from the image and those changes does not apply to the existing machines in that catalog.

The problem occurs because the update process assigns the new updated image to all the Virtual Machines in the catalog, marking the existing ones with the ImageOutOfDate flag. Once the flag is enabled for the Virtual Machine, it shuts down after logging off with the attempt to start to the newly assigned image. At this point, the flag is always enabled since Dedicated machines cannot change to a different image.

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Technical Support of Microsoft Lync on XenDesktop

As stated in Client Virtualization in Microsoft Lync 2010 (http://www.microsoft.com/download/en/details.aspx?id=21129), republished by Microsoft in February 2012, delivery of the Lync 2010 client using XenDesktop and XenApp is “Supported” by Microsoft (see Table 2 on page 7). However, audio (voice chat) is not directly supported by Microsoft (see Table 3 on page 8) except through a desk phone using USB Redirection. Likewise, video chat is not directly supported by Microsoft. These statements are based on XenDesktop 4.0 and XenApp 6.0 (see Appendix A.1, page 12). As noted in the footnote on page 13, “XenDesktop 5 (which introduces webcam video compression as an alternative to USB redirection) was not tested.”

How do these statements impact Citrix customers who wish to deliver Microsoft Lync with voice and video chat functionality from XenDesktop 5.5/5.6 or XenApp 6.5?

In short, XenDesktop/XenApp delivery of Microsoft Lync, including voice chat and video chat, is fully supported by Citrix.

Microsoft does not directly support third-party products such as XenDesktop. In our experience, customers can expect “best effort” support from Microsoft but in some cases might be asked to duplicate a problem on a regular PC with no Citrix software installed.

Citrix supports the delivery of Microsoft Lync and other similar third-party Unified Communications clients and softphones from XenDesktop (including XenApp) to users of the Citrix Receiver through a variety of innovative technologies. These include the Optimization Pack for Microsoft Lync introduced with XenDesktop 5.6 Feature Pack 1 and XenApp 6.5 Feature Pack 1, and a set of generic HDX RealTime technologies which are compatible with Microsoft Lync and its predecessor, Office Communicator.

Highlights of the Optimization Pack for Microsoft Lync include:

  • Offload of all media processing from the Citrix server to the user device via the HDX RealTime Media Engine plug-in to the Citrix Receiver (initially available for Windows and Linux), thereby maximizing server scalability
  • Native support for Microsoft’s proprietary RTAudio and RTVideo codecs without transcoding
  • Up to 720p30 transmit and receive resolutions using H.264
  • Peer-to-peer media transport via RTP (only signaling goes over ICA)

Generic HDX RealTime technologies that are compatible with Microsoft Lync include:

  • Optimized-for-speech codec technology, featuring fast encode and low bandwidth utilization
  • Webcam Video Compression in the Citrix Receivers for Windows and Linux, offering excellent bandwidth efficiency and network latency tolerance
  • Jitter buffering in the Citrix Receiver for Windows to ensure smooth audio even when network latency is variable, and Echo Cancellation when using a microphone and speakers instead of a headset
  • Audio plug-n-play
  • Audio device routing (for example: ringtone can be directed to speakers but voice to a headset)
  • Multi-stream ICA transport for full QoS support
  • UDP/RTP audio option on XenDesktop VDI
  • DSCP packet tagging for RTP packets (Layer 3)
  • WMM tagging for Wi-Fi
  • Branch Repeater support for QoS and multi-stream ICA, including UDP

Furthermore, Citrix is committed to fully supporting the next release of Microsoft Lync, codenamed “Wave 15”.

Here’s the link to the original KB article.

Personal vDisk Technology Planning Guide

Citrix has released a planning guide for XenDesktop 5.6 personal vDisk implementation.

Guidelines

Personal vDisks are available in all versions of XenDesktop 5.6. Generally, the use of a Personal vDisks is evaluated when there is a strong desire for personalization of the virtual desktop. This could include a need to use a variety of departmental applications with a small, distinct user groups or general personalization that is beyond what is available in the user profile. However, there is no defined limitation of Citrix Personal vDisk technology to these specific use cases. It is entirely possible to utilize Personal vDisks in scenarios that may not maximize flexibility or virtual desktop density, yet are entirely appropriate to the enterprise environment.

The use of Personal vDisks should be part of the consideration of most virtual desktop implementations, particularly when considering Dedicated Desktops. When considering Personal vDisks, the following topics should be reviewed during a virtual desktop implementation design. Continue reading “Personal vDisk Technology Planning Guide”