Month: November 2016

PVS write cache full issue crashing your VDI’s? check following if using Outlook

Seen this issue cause some pain recent enough.


XenApp 6.5 HRP05

Published Desktop running W2008 r2 and Office 2013 using PVS 7.9 golden images

Received reports of users getting hung sessions. On reviewing system see it can’t be RDP’ed too, completely froze. Issue caused by write cache spilling over from RAM onto hard drive and filling hard disk.

Root cause

What caused the write cache to blow up was chiefly offline address books being downloaded every time the user logged into outlook. As our environment is quite large these are in around the 500mb size range. With these systems being rebooted once a week and often times 10 logons on a system in a given day quickly noticed write cache growth across the board by Wednesday’s precipating reboots.

In order to fix we needed to disable download of the Offline address book when users’ accessed Outlook. We run in a cached mode in Exchange but was fine to disable the need to download.

Key is to add the registry hack in

and we were good to go


Handy URL’s relating to 2012 r2 RDS environments

2 areas’s that always need some TLC are patch management and AV. Enclosed couple of URL’s relating to them:

For patch management (covering various RDS roles):

Recommended hotfixes and updates for Remote Desktop Services in Windows Server 2012 R2

For Anti-virus




Citrix Project Accelerator – Design phase

Yesterday kicked off a mock project assessment ( using the Citrix Project Accelerator tool to assess its strengths and weaknesses as a tool an SME might be able to yday. Covered the Assess phase which basically required me to input details about my environment.

Couple of items sprung out for me regards the design phase:

i) Hypervisor choice – interesting the citrix decision was to plump for vSphere. My inputs didn’t measure anything i didnt think that wouln’t warrant recommending their own hypervisor (XenServer)

ii) Updates – It appears like the choices haven’t been updated in a while. For instance XenClient is referenced even though that is EOL now also for Desktop OS choice it gave a recommendation to go Windows 8.1 and Windows 10 wasn’t even on the list.

That said i do think it would have value in at least providing some general recommendations that for the most part would be applicable to nearly all types of environments as a rough starting guide. Obviously scalability testing/more thorough application testing would help refine the figures somewhat.


Enclosed shots showing citrix recommendations made based on my inputs from previous.

Rolling out a Win8/10 VDI solution ? be aware of following

Firstly an absolute “must read” from the guys Dan Allen and Nick Rintalan around the area of codecs and bandwidth.

Protocol & Resolution Impact on Bandwidth and Scalability

Particularly for folk migrating from Win 7 to 8 or later couple of items piqued my interest (slide 25).

i) Desktop Windows Manager (DWM) can no longer be turned off

ii) GDI/GDI+ was deprecated

On previous iterations of OS hadn’t placed a large emphasis on codec testing (fewer options/scenarios for one) but in the new environments with all the options that comes with it essential the right “mix” is found based on your application set

Citrix PVS tip: Getting dreaded “Manifest file is invalid” message?

Check if running Citrix PVS 7.8 or earlier. I’ve had the unfortunate experience of getting this numerous times trying to import an new vDisk version of a VHDX file, unfortunately for me I was running 7.1 at the time and no fix was imminent when I spoke to vendor.

Good news is as of PVS 7.9 issue is resolved.

Utilizing the Citrix Project Accelerator for my Pidgey Inc. project

Recently with dwindling resources have had to wear more and more “hats” in my day-to-day activities. One of which was technical project management. To that end recently sat the PRINCE2 foundation exam (squeaked it, phew!). One thing did like with the methodologies used around the PRINCE2 framework was its common sense approach. Wasn’t just a case of “paperwork for paperworks” sake.

With that in end wanted to take a look at creating a new environment in the lab (located in my Azure lab environment) and review the approach taken with the Citrix Project Accelerator(URL:

The Project accelerator is a tool that is mentioned early on in the Citrix Virtual Desktop Handbook (pg3) which is described as “an interactive online tool creating customized sizing and design recommendations based on the methodology, best practices and expert advice identified within this handbook”

To that end thought it would be fun to set up my dummy organization (Pidgey Inc. in this instance (Pokemon Go reference :)) and review the data coming out of the questionnaire.

For this piece will cover the Assess stage and follow up with the Design section next. citrix-project-accelerator-assessment-stage


Hitting a ceiling on your VDI user count? Good time to review your user persona’s

Recently being carrying a review of our usage across the various desktop/application virtualization platforms and noticed an interesting trend in that our usage figures have pretty much tapered off as such “hitting a crossroads”.

Was interesting in our instances for the following reasons:

  • previously we had some nasty outages which obviously heavily impacted both user experiences and management perceptions of the product
  • been over 2 years since such outages so from that viewpoint the service is both running very reliably and from a server/host resource point of view performing well within tolerances
  • Headcount was risen quite appreciably in the past 2 years so not withstanding the user groups who had a non-VDI requirement certainly quite a few user groups who had employed VDI previously that where moving back to a traditional platform.

Which bought up an interesting article posted up on the Citrix blogs relating to customer centricity.

How Do I Ignite the Mindset Shift to Customer Centricity?

In a way the tapering off effect has given us an opportunity to provide a fresh perspective on the product and see what we can do to improve it but this time with a much more customer-based focus. In terms of the interviewing pieces had some of my slants to add (will be reaching out to business owners soon).

So to that end reviewed with the help of human resources a break-up of the major groups in the organization (any team with >500 being the rationale) and from there looking at fitting them into a persona breakdown.

What are persona’s you say?

In essence they are a practical way to identify the requirements of your end user base.

Why are they important?

Understanding how users’ operate on their day-to-day work activities. How long using mail, custom app requirements, slow performance “kinks” experienced throughout the day.

Typical persona’s include:

Knowledge worker

Task workers

Call Center


Plenty of Persona templates out on the web. Below gives a breakdown of some of the key factors to consider when assessing the suitability of a user to using a VDI platform as opposed to a traditional platform. Below is an example of the breakdowns. Still gathering data my end and interviews to start soon.