Recently I deployed Citrix XenApp 6.5 on virtual machines using a template I had previously created. The machines provisioned without error, and appeared to be working properly. Unfortunately, I was unable to open a remote desktop session onto the virtual server. After researching the issue, I found a registry entry that corrected the problem. I added a new DWORD called “IgnoreRegConfigErrors” with a value of “1″ to the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server directory.
Other troubleshooting methods that may be useful are disabling any unused NICs on the server, and disabling IPv6 if using IPv4.
In previous releases of Citrix’s XenApp solution, every server in the Farm was required to download all of the Farm’s data to its Local Host Cache when joining. This process consumes large amounts of bandwidth, which on a WAN connection can be especially problematic. Not to mention, the XenApp servers were forced to devote resources to the overhead processes involved with maintaining numerous read/write operations with the IMA datastore.
To resolve this issue Citrix has created a separate “Worker” role for servers joining a XenApp 6.5 Farm. With this role installed, the servers operate in a “Session-only” or “Session-host” mode. These servers operate with the one task of hosting user sessions, and as a result only need to sync a subset of data to their LHCs. Meaning that these servers operate with much less overhead than a traditional “Controller” mode server allowing them to join the Farm much faster, consume less bandwidth, and consume less resources overall. On the flip side, these hosts are unable to serve as Zone Data Collectors, perform XML brokering tasks, and/or participate in IMA elections.
The server mode is selected when first joining the machine to the XenApp Farm. To switch modes, the server must leave then re-join the Farm. A well planned XenApp 6.5 deployment with the right quantity of Controller and Worker servers allow for a significant performance improvement over environments with a previous version of XenApp installed.
For some time now system administrators have struggled with presenting users in a terminal server environment with a Windows 7 type workstation without deploying a full VDI (Virtual Desktop Infrastructure) solution. Now with Citrix XenApp 6.5, employees using a shared server desktop can instead be given a desktop that mimics the look and feel of a full Windows 7 machine.
The technology is titled “Windows Desktop Experience Integration”, and it can be installed via the Server Role Manager. The process for enabling and deploying this solution is very simple. When Windows Desktop Experience Integration is installed, a PowerShell script called “New-CtxManagedDesktopGPO.ps1″ is placed in the “Program Files (x86)\Citrix\App Delivery Setup Tools” directory. Launch this script and four new Group Policy objects will be added to your Microsoft Group Policy Manager application. The policy titled “CtxStartMenuTaskbarUser” will enable the Windows 7 user experience. Link this policy to the OU containing your XenApp servers with published desktops, and you are good to go. The other three policies allow for more granular user/computer management in the XenApp session.