Tag Archives: citrix

XenServer PVS Accelerator Sizing – Part 2


As you might have read, I recently ran a few XenServer PVS Accelerator tests to determine a starting point for the cache size.  This initial investigation looked at Windows 10 and Windows 2012R2 for boot and logon operations.

Looking back, I determined that I want to include three additional items

  1. Impact of a larger cache size – Increase from 2GB to 4GB RAM cache
  2. Impact of applications
  3. Impact of Windows 2016

Before I get into the results, let me explain the graphs.

  • The blue, green and orange line denotes boot, logon and steady state operations. The first time those colors appear depicts the first VM; the second time the colors appear depicts the second VM. These colors are linked to the axis on the right showing percent of cache used.
  • The solid red area graph depicts the amount of network traffic sent from the Provisioning Services server to the host.  The line should initially be large and then diminish as the cache is used. It is linked to the left axis with bytes per second.

With that understanding out of the way, let’s look at the results.

Continue reading XenServer PVS Accelerator Sizing – Part 2

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How does Workspace Environment Management Improve Windows Logon Time


I’ve been able to experience the results of implementing Workspace Environment Management into a Citrix XenApp and XenDesktop environment.  I was easily able to obtain at least a 50% reduction in logon duration.

I understand the why.

I want to now understand the how.

Let’s first examine the Windows logon process.

Continue reading How does Workspace Environment Management Improve Windows Logon Time

Your network is hurting your application experience


A few times a year I get addicted to Xbox. Once the kids go to sleep, I can easily spend hours playing Mass Effect, Fallout or Assassin’s Creed.

The games are wonderful and immersive, which is why I spent over 100 hours playing Fallout 3 and another 100+ hours in Fallout New Vegas.  Unfortunately, I’ve experienced some annoying things with these games.  I’ll be in one of the final battles of Mass Effect 3 against the Reapers when the game starts stuttering.  Do you know how hard it is to aim when the system stutters?

Game stuttering, system stuttering or application stuttering is a great way to severely hurt the user experience. How can we reduce app stutters? We need to look at the underlying reason for the stuttering and figure out how to correct.

Network latency and packet loss is a big reason why users might experience stuttering in an application. If a packet gets lost or a packet times out due to high latency, that packet must be retransmitted.  Retransmissions take time. And if you experience a lot of retransmissions, you experience a lot of application stutters.

We’ve already seen how Citrix’s Adaptive Transport impacts

  1. File Copying
  2. Video Viewing

But what does it do to the application experience? See for yourself

Daniel (Follow on Twitter @djfeller)
Citrix XenApp and XenDesktop 7.6 VDI Handbook
XenApp Best Practices
XenApp Videos

 

 

 

Your network is hurting your video viewing experience


I just binged watched the first season of “The Expanse”. Awesome! (BTW, the books are even better.)

I would say 90% of my TV viewing is done with streaming media either from Netflix, Amazon or my home library. Nothing is better at ruining a good viewing session than the spinning circle of oblivion as the video stream is being loaded.

Unfortunately, I had the unfortunate experience of watching that spinning circle of frustration multiple times per episode. Running an Internet speed test revealed I had plenty of bandwidth but, for some reason, my latency was through the roof (400+ms).

My solution was to reboot my cable modem and wireless access points throughout my house. This always fixes the problems. I even made it easy for my family to reboot the system when I was traveling.

What I find interesting about this experience is how latency, and not bandwidth, can impact the viewing experience of video content. Lucky for me, the solution was easy… Reboot. But what if the latency isn’t a technical challenge, but more of a physical challenge based on the location of the viewer and the location of the content?

How can we overcome poor network latency and packet loss?

In a previous video that talked about Adaptive Transport, the focus was on file copying.  The results were astounding.

The question now is, would Adaptive Transport also have an impact on the video viewing experience?

Short answer: Yes. Yes it does.

And just in case you were worried about me and my personal happiness, I did fix my home network issues by replacing my WiFi router with better WiFi access points. No more rebooting devices every 2 days.

Daniel (Follow on Twitter @djfeller)
Citrix XenApp and XenDesktop 7.6 VDI Handbook
XenApp Best Practices
XenApp Videos

Your network is killing your file copy performance


We’ve all been there before, rush hour traffic.

You know how it goes. You slowly increase speed to 5mph, then 10, then 15. Excitement is building because you are now going 20mph. Then, out of nowhere, you slam on the brakes and your speed immediately drops back to 0mph. We eventually start over again, 5, 10, 15mph before we slam our foot on the brakes again bringing us to a complete stop.

At this point it is OK to yell “SERENITY NOW!!!

Unfortunately, this is how packets are being sent across the LAN/WAN. This is how TCP functions via the AIMD (Additive Increments, Multiplicative Decrements) congestion control algorithm. TCP slowly increases transmission speed and then drastically falls back when a re-transmission is required due to a timeout, collision or packet loss.

This works fine on a LAN where bandwidth is high, packet loss is low and latency is low. But as latency and packet loss increases, as is common with a WAN environment, TCP is never able to get up to full speed. We are left with only partial utilization of our WAN link.

We see this all of the time when we try to copy a file. On a LAN, the speed of the file copy remains fairly constant, but on a WAN, the bandwidth utilization slowly increases before dropping back to 0, just like rush hour traffic.

Look at what Citrix did!

Adaptive Transport is able to overcome WAN latency and packet loss. It makes a simple task, like file copying, twice as fast as a traditional Windows 10 PC and 3 times as fast as a VMware Horizon desktop.

Adaptive Transport is an alternative to traditional TCP. And it is more than simply a switch to UDP. Adaptive Transport is a newly developed Citrix enlightened data transport optimized for WAN environments by overcoming high latency and packet loss resulting in faster file copying.

protocol

If the network supports the new transport, HDX will use it. If it does not, HDX falls back to TCP.

Daniel (Follow on Twitter @djfeller)
Citrix XenApp and XenDesktop 7.6 VDI Handbook
XenApp Best Practices
XenApp Videos

Citrix VDI Handbook 7.6


The Citrix VDI Handbook is now available!

Let me answer a few questions about the VDI Handbook

  1. Version: The VDI Handbook is based on the XenApp and XenDesktop 7.6 Long-Term Service Release.
  2. Updates: The plan is to release a VDI Handbook for each Long-Term Service Release. The VDI Handbook is based on real-world implementation experiences. Basing updates on LTSR releases (18-24+ months) allows us to include better recommendations than if we updated for the current release (every quarter).
  3. Format: PDF and HTML. The PDF version is ready now, the HTML version will be ready shortly.
  4. Content: The handbook includes information on Assess, Design and Monitor.

Grab version 1 of the Citrix VDI Best Practices Handbook for XenApp and XenDesktop 7.6

Daniel (Follow on Twitter @djfeller)
XenApp Advanced Concept Guide
XenApp Best Practices
XenApp Videos

 

 

Citrix VDI Handbook


At Citrix Summit in January 2016, I heard from many of you asking for an updated version of the Citrix VDI Handbook.

At Citrix Synergy in May 2016, I heard from many of you asking for an updated version of the Citrix VDI Handbook.

At BriForum in July 2016, I heard from many of you asking for an updated version of the Citrix VDI Handbook.

To me, it sounds like you want the Citrix VDI Handbook to be updated.

The good news.  It is being updated!!!

The better news. We got our Citrix consulting experts to validate the recommendations

The bad news. It isn’t ready yet.

So why am I telling you this?

First, you can stop hounding me about getting it updated.  It is happening.  I am currently buried in Microsoft Word.

Second, I need to know if there are things missing that you think should be included.

And third, does this news make you happy?