Technical Deep Dive: XenApp Load Evaluators

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One of the often overlooked features of XenApp is truly understanding the load evaluators. As a consultant, I commonly see environments using only the Default Load Evaluator. If I am lucky, they might be using the Advanced Load Evaluator. Rarely do I find organizations actively monitoring or customizing their load evaluators.

Load Evaluators have not changed much since Presentation Server days, but amazingly they are not commonly optimized. Every environment and every workload is different, so whichever load evaluator is implemented may vary, but they should be customized and monitored.

Are you ready for VDI?

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More companies are investigating the benefits of implementing a Virtual Desktop Infrastructure (VDI).  If you are one of those companies then you need to ask yourself, “Am I ready for VDI?”  The first step is identifying exactly what VDI means to your organization.  VDI actually encompasses several types of delivery, but is most commonly associated with what Gartner classifies as hosted virtual desktops (HVD).  VDI can also include implementations of server-based computing (SBC), hosted shared desktops (HSD) and client-side virtualization.  For the sake of simplicity, we will focus on the hosted virtual desktop model for VDI since that is the most common assumption of a VDI deployment.

Citrix Synergy 2011

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If you are thinking about going to Synergy this year, I will be assisting in moderating the XenClient learning labs (SYN409D) during Summit and speaking as part of the XenDesktop team during Synergy. This is an exciting opportunity for me! If you are planning on attending, check out the 5 part WOW TO HOW Series, I will be speaking on Part 3: Storage Infrastructure (SYN305)

For more information on Synergy, or to register, follow this link: Synergy 2011

To see more details on my session, follow this link: SYN305

XenDesktop 5 Deep Dive: Machine Creation Services (MCS) on vSphere 4.1

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As promised, I have published my Deep Dive around MCS over at The GenerationV Site: http://tinyurl.com/4tzpfts. Check it out!

The data is abstracted, but all the source came from a real-world pilot. The question posed was, "What is the impact of MCS on storage and how exactly does it work on vSphere?" So, I rolled up my sleeves, dug in, and figured I would share my findings.

In short, MCS works as design and can greatly save on storage space by using a linked snapshot as well as save on administration by rapidly deploying machines. The downside becomes when you need to move machines to different storage. Not always a common event, but one to consider.

Personally, I still prefer PVS for an enterprise-scale deployment, but MCS has it's place.


Other resources:

• XenDesktop Design Handbook Success Kit  - One stop shop for XD Resources
• Citrix XenDesktop Architecure Series  -  Citrix Community Blog for XD Architecture
• Dan Feller's Blog- Great Architectural Resource for XenDesktop

It's been awhile...

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WOW.  It's been awhile since posting, but I have a lot of topics in the pipeline.  Since joining GlassHouse, I figured I would have more time to write, but the inverse has turned out to be true.

However, thanks to some recent requests, I am back on the blog.  Here are some things to look for in coming weeks:

• VDI preparedness -- what you need before you jump into virtual desktops
• Deep Dive into MCS -- XenDesktop 5's new Machine Creation Services
• Deep Dive into WI on NetScaler -- the new Web Interface integrated directly onto NetScaler VPX
• Deep Dive into XenDesktop 5 -- notes from the field on what's new and improved plus evolving best practices
• 7 Rules of Consulting -- written as a series, my own personal take on being a consultant

Joining GlassHouse Technologies!

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I'm happy to announce that I have joined the team at GlassHouse Technologies as a Senior Virtualization Consultant. With this role, I will be tasked with helping manage virtualization projects, with a main focus on Citrix Technologies.

My main focus will be on expanding our XenDesktop / Virtual Desktop offerings, and will leverage all of our corporate expertise on Datacenter Management, Virtualization, Storage and Security.

Citrix closes the gap with VMWare -- XenServer 5.6 Beta, Part 1

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Most of the complaints I've heard in regards to XenServer vs. VMWare is the fact that XenServer does not allow an overcommitment of memory.  If you have a host server with 16 GB of RAM, you can only allocate up to 16 GB of RAM for the guests (yes, I know, technically less since Xen requires some resources... but you get the point).

Personally, I'm not a fan of over-allocating memory.  I actually like that with XenServer, I do not have to worry about it.  I've seen too many VMWare farms suffer because of assigning too much memory then having to constantly swap resources.  I think if you engineer the solution correctly, and size your servers properly, memory allocation should be kept in check.

However, seeing this as a fault when comparing virtualization host platforms, Citrix has released the latest Beta of XenServer 5.6.  One of the new features IS allowing your to over-allocate memory... they call it Dynamic Memory Control.  I have to admit, it is pretty cool and very easy to use.  The XenCenter display makes it VERY intuitive... all the better to see WHERE your resources are allocated, especially when squeezing memory.

 
To read more technical details, see my full article at: http://www.thegenerationv.com/2010/04/xenserver-56-preview-part-1-dynamic.html