Posts

The case of the Slow Xerox Universal Print Driver

Xerox LogoEarlier this week I was asked to investigate a problem with the Xerox Universal Printer Driver. Users complained that printing to a Xerox printer was much slower than printing to an HP printer.

Excel 2007 IconI received a reference document from a user, a rather complex Excel sheet. When selecting multiple tabs it took almost a minute to generate a print preview in Excel 2007 running on Windows 2003 with XenApp 5.

I was aware of a bug in the Xerox Universal Driver where almost 9.000 files were copied into the user’s profile directory (I wrote about that in an earlier post). But this seemed to be another problem.

 

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Please wait for the Local Session Manager

Author : Ingmar Verheij
I’ve built a lab to run some tests on Citrix XenApp. Since this is a lab environment I do not have enough resources to create dedicated machines for each role. Therefore I found it justified to create a virtualized domain controller (dc001.domain.local) with multiple roles and multi-homed (Boooohhh, I know). The machine is not only a domain controller but also has the DNS and DHCP role.

The following network interfaces are present on dc001.domain.local:

  • Local Area Connection 1 : 192.168.1.1/24
  • Local Area Connection 2:  192.168.2.1/24

The Citrix XenApp server is a dedicated physical machine with a single network interface:

  • Local Area Connection 1 : 192.168.1.2/24

After creating a published desktop I’ve tried to connect from a machine in the 192.168.1.0/24 subnet. The session keeps waiting with the message ‘Please wait for the Local Session Manager’.

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VMware shared folders keep profiles in use

Author : Ingmar Verheij

VMware Shared Folders

When Microsoft Windows systems are virtualized with VMware ESX or Workstation, WMware Tools is installed. When the VMware tools are installed with the Complete option, the shared folders option is enabled. This feature is not enabled when you install VMware tools with the Typical option.

The shared folder feature is not supported by ESX or GSX server and causes problems on Terminal Servers. The file hgfs.dat is opened by the VMware Tools with exclusive acces, which prevents the profile from getting deleted.

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The impact of Silverlight on a virtual desktop

Silverlight Logo[4]

A customer has a (virtualized) Citrix XenApp farm scaled for 1500 concurrent users. The environment is based on Windows Server 2003 Standard with Citrix XenApp 5 (migration to XenApp 6.x is scheduled).

A business critital web-application is re-developped and requires Microsoft Silverlight. Before implementing Silverlight the impact should be determined. A big concern is a decrease in the capacity of the farm, number of concurrent users the farm can handle.

To determine the impact of Silverlight I’ve done some tests, including a LoadTest.

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VMWare Best Practices for virtualizing Citrix XenApp

VMware has just released a very interesting Best Practices document, Citrix Xenapp on VMWare Best Practices.

The document contains the following chapters:

  • Citrix XenApp Architecture on vSphere
  • ESX Host Best Practices for Citrix XenApp
  • Citrix XenApp on vSphere Best Practices
  • Monitoring Performance
  • vSphere Enhancements for Deployment and Operations

DeNamiK LoadGen 2.1 is released!

DeNamiK is proud to present the DeNamiK LoadGen 2.1. With the DeNamiK LoadGen it’s possible to perform the following actions:

  • Load test
  • Stress test
  • Performance test
  • Constant monitoring
  • Benchmark
  • Reporting

With the DeNamiK LoadGen 2.1 there are lots of new features and improvements. Let’s name just a few:

  • ICA File support
  • Performance Counter module 2.0
  • Internal processes are optimized

The DeNamiK User Action Framework for XenApp has been updated:

  • More DUAF functions which will help you create more reliable scripts
  • Status updates possible from the LoadBots to the Director and to the reports
  • XML reports available

Also one of the best changes: the LoadGen moved from .Net Framework 1.1 to:

  • DeNamiK LoadGen Director: .Net Framework 3.5
  • DeNamiK LoadBots: .Net Framework 2.0

Read the whole article on the website of DeNamiK!

Daniel Nikolic

Client File Security

In the Citrix ICA client, or XenApp Client Online plug-in, the access to your client drives is protected.
The first time you access your client drives the client will ask to allow (or disallow) the access. This message looks like this:

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Download older versions of the Citrix ICA Client

The current version of the Citrix ICA client (Online Plugin 12.0) no longer supports the Program Neighborhood, as my colleague Jeroen Tielen has wrote in the following article http://www.peppercrew.nl/?p=563

Some customers are still using implementations that will need the Program Neighborhood client. One customer was using an old version of the ICA client to connect to an remote Presentation Server Farm. The version of the ICA client that the customer was using did not support XML-browsing over https. The new configuration of the remote Presentation Server Farm aspects that XML browsing is done across https, so the customer is needing an newer version of the ICA client, but not the newest as the remote Citrix Farm does not have a Citrix Web Interface in place.

The Citrix client download site only holds the latest version of the ICA client. There is no history on this site . The site http://www.xenappblog.com/downloads/?category=2 does contain download links for older versions. Here you can download the latest version of the ICA client that still contains the Program Neighborhood (version 11.0, Citrix XenApp Plugin for Hosted Apps)

Stresstest your printer drivers

A few days ago I wrote an article about the issues with printer drivers in a multiuser environment. In this article I advised you to test you’re printer drivers in a acceptance environment, preferably with real users testing. This can be achieved with a LoadTest / StressTest tool like the Denamik LoadGen, which is free up to 25 users. And since testing with 10 users is enough to stress a driver, there’s no need to buy a license.

Today I would like to tell you how this is done, step-by-step.

The goal
We’re going to try to use the printer environment as realistic as possible, but where focusing on the worst case scenario. Because where trying to find out whether the printer driver is functioning correct when multiple users are printing, where going to simulate that a number of users are printing to printers using the same printer driver.
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XenDesktop 4 released, XenClient delayed.

Yesterday I spoke a representative of Citrix in The Hague. Topic of discussion was XenDesktop, XenClient and why the release of XenClient was delayed to Q1 2010.
Last June Citrix CEO Mark Templeton announced XenClient to be released in H2 2009, for free. This was during the openening keynote at iForum in Antwerp (this was already announced at Synergy).

What is XenClient?
For those of you who don’t know what XenClient is, XenClient is a client hypervisor for desktops / laptops. The client hypervisor creates an isolated environment for multiple virtual machines with (almost) native performance. This solution (probably) creates the following use-cases:
– Private and work environment (completely isolated from each other);
– Multiple OS versions running at the same time during transition (XP / Win7 / MacOS);
– Demo’s with multiple VM’s including a console (instead of a master image and type 2 vm’s);
– On demand streaming of OS to desktops / laptop (instant migration!);
– Offline VDI in combination with XenDesktop;
– Single image for all models (especially useful with laptops);
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