Blog posts tagged with 'virtualization'

The St.Bernard iPrism works with Citrix's Application Virtualization platform - XenApp, and works quite well. Seen as a perfect complement to each other the Citrix NetScaler and XenApp products were tested with the St.Bernard iPrism Web Filter. Both companies offer architectures of one-arm (out-of-band) and two-arm (in-band) deployments. At Citrixlabs in Santa Clara, CA, USA, we tested both the out-of-band and in-band configuration of the iPrism Web Filter. We loved the fact that the iPrism is auto-discovered by the management software, so no console cable was needed.

With NetScaler:

We deployed the iPrism Web Filter behind the NetScaler in our proof of concept datacenter in Santa Clara, CA, USA, and configured the NetScaler for NAT (Reverse NAT) for outbound connections to the Internet. NAT is often performed by the Firewall. The Web Application Firewall, also part of the Citrix NetScaler, was configured for protection of inbound security threats to websites and web applications.

The iPrism was configured to monitor outbound traffic from the internal subnet of 172.16.104.0/24, and block all traffic to offensive websites, and monitor traffic to all other websites. The Real-Time monitor in iPrism gave us a detailed report on the users and IP Addresses that were going out to which sites on the internet. We could see who was accessing what, and which content was being blocked. Particularly nice, was the fact that the iPrism automatically authenticated each user to the Citrixlabs domain controller, every time they surfed a new website, without them knowing it. This was very useful for keeping a tight grip on security and for compliance reporting.

With XenApp:

The powerful value is in the integration with XenApp. We plugged the iPrism in as an in-line device, and configured it to work with Citrix XenApp©, formerly known as Citrix Presentation Server. One of the key questions that will arise in this situation is with all of those Citrix XenApp thin clients logging into the XenApp and then launching browsers to the internet, how does iPrism keep track of them. By adding the XenApp IP Address to the iPrism configuration, the users are tracked using "Session Based Authentication" - this catches each individual user and IP Address in each browser session and in the reports. We were impressed by this and determined the iPrism to be an excellent fit into a datacenter outfitted with Citrix.


Citrix & St.Bernard Deployment Guide!

Network Diagram:

Watch this video tip:

NetScaler Developer Network!

This is the very first edition of a highly buzzed virtualization event held in London, UK, from Oct 14 to 16. The event is three days long: first day (Oct. 14) is dedicated for distributors and resellers, second and third day are for the attendees.

But wait a minute. Another trade show? The answer is, Not really!

So what makes Virtualization Congress special, VC is shaping up to be a truly unconventional conference.

• No Slide allowed on Stage - Only 1-hour long demos: the product is being showed while applied to a specific use case, hopefully matching the ones that attendees may have back at their datacenters.
• It's independent, following the very successful model we know from BriForum, Virtual Congress is an independent and unbiased conference.

Never mind the level of expertise attending the conference: Simon Crosby, Mark Russinoivch, Richard Garsthangen, Scott Herold and many others.

Citrix as usual will be there supporting the conference as a platinum sponsor and deliverying the keynote, you will be able to interact with our top experts and product specialists, so feel free to stop by our booth and say hi to myself, Simon, and others.

Anything else? Yes. Citrix Certified individuals (CCA, CCEA, CCIA) will receive an amazing discount to sign-up for the conference, an amazing 25% off the regular price or $400 US dollars for a pass. *Details coming soon, stay tuned.

I'm looking forward to this event and I have here a video invite from Simon to share with all.

In the meantime you can check out the following links for more information.

Home
Speakers
Agenda

See you in London.

best,
Gus

Live Webinar: "Citrix & Hyperic: Best Practice for Successful Virtualization Systems Management"

 

Hyperic's enterprise-class management and monitoring software for the popular Citrix XenServer virtualization software provides users with a single view into their virtual and non-virtual infrastructure. Join Citrix and Hyperic for their upcoming webinar to learn more about this best practice solution for successful virtualization systems management. Reserve your space today, register here: https://www1.gotomeeting.com/register/999023087

Memory is a big concern for XenApp on a 32bit operating system like Windows 2003 Server.  In the default state, Windows 2003 can only "see" 4GB of memory, which is split up into two equal parts: Kernel Memory (2GB) and User Memory (2GB). Kernel Memory is further broken down into 4 other parts:

• Paged Pool: Memory space used by the system and kernel level components that can be paged out of physical RAM and into the page file
• Non Paged Pool:  A section of memory guaranteed to always reside in physical RAM and is used by the operating system for certain kernel level processes
• System Page Table Entry : An index table that tells the operating system where the virtual memory actually resides in physical RAM or on the page file
• System Cache: Maps open files in memory for better performance. This is where the registry hives are located as well
  

Once the system has started, the different sections of kernel memory cannot be re-allocated. The system tries to allocate these 4 areas appropriately, but they might require "tweaking". However, the four areas cannot all be set to the maximum level as that would go over the 2GB limit of kernel memory.

Many of you are probably saying, "But I can use the PAE switch on Windows 2003 to go above the 4GB limit". You are correct, you can go above the 4GB limit, but are you aware of the consequences of this action?

1. You must be using Windows 2003 Enterprise or Data Center.  This setting does not function in Windows 2003 Standard.
2. The PAE Switch does NOT change the kernel memory limitations of 2GB
3. To use the extra RAM, more System Page Table Entry memory is used
4. If you have more System Page Table Entries, you will end up with less Paged Pool, System Cache and Non Paged Pool
   

Talk about being between a rock and a hard place. Adding more RAM and enabling the PAE switch "might" give you more scalability but at a great cost for a more expensive operating system, more RAM and special optimization configuration analysis and implementation. The reason I said "might" give you more scalability is because you will now likely run out of kernel memory before you run out of user memory. So you just bought a more expensive operating system and more RAM that will sit there wasted. 

Now I know some of you will add a comment saying something to the effect that you are using the PAE switch and ended up increasing single server scalability by 60, 70, 80 or even 90%.  All I can say is congratulations and I applaud you  . You are lucky as you have the right set of apps for this to work as well as it has.  But I want you to think about going down a completely different route.  Virtualization...

Keep using Windows 2003 Standard but virtualize it with XenServer. Upgrade the RAM on the physical servers so it can support 2-4+ virtual servers. In the end, you will end up with a system that is more flexible, scalable and easier to manage. 

If you interested in learning more about sever virtualization for XenApp, then take a look at the following:

• TechTalk Recording: Make Server Virtualization work for XenApp (http://www.citrix.com/English/NE/events/event.asp?eventID=1679445)
• White Papers
  • Reference Architecture
  • Implementation Guide
  • Design Considerations

Daniel

Homer Quote of the Blog: "To be loved, you have to be nice to others EVERYDAY! To be hated, you don't have to do squat."

One of the features of the Citrix Delivery Center Podcast is called the Citrix Countdown. The Citrix Countdown is focused on giving insight into our Knowledgebase articles and Citrix Technical Support in top five countdowns.

In the first Citrix Countdown on Episode One, Jim West from XenServer Technical Support counts down the top five most popular XenServer Knowledgebase articles over the last 30 days.

Here is the list from the first ever Citrix Countdown -

Listen to the Citrix Delivery Center Podcast to hear Jim cover each article in brief.

Citrix is all about virtualization. They have a suite of tools that enable IT departments to virtualize almost everything. Citrix is a Microsoft Certified Partner and, to some extent, a competitor. How does this Partner Competitor relationship work? Microsoft is very interested in virtualization technologies and with the advent of our hypervisor technology, HyperV, and application virtualization software, SoftGrid, you can bet that we'll compete hard with other virtualization vendors.

Here, we meet Simon Crosby, formerly of XenSource now working for Citrix (Citrix purchased XenSource). We discuss the relationship between Microsoft and Citrix, the complexities of building scalable, sercure, reliable and performant virtualization technologies and the future of virtualization. It's a very interesting conversation and Simon is quite the conversationalist. Enjoy.

Now that the first Citrix Delivery Center Podcast is completed and posted, I am looking for suggestions on topics for future podcasts. Episode Two will be cover the scalability testing of XenApp on XenServer. What would you like to hear in future episodes? Are there particular topics that interest you, or would you like to hear from a particular person? Vote below and let me know.

I am trying out a new third party poll (PollDaddy - flash required) that allows for multiple choice votes.

UPDATE:I have added three new options based on emails I have received. "How to Speed Up XenApp Logons", "Provisioning Server Deep Dive" and "Using WorkFlow Studio".

In case you haven't heard or seen , I'll be hosting a live TechTalk on Wednesday, July 23rd at 1PM Eastern covering the virtualization of XenApp on XenServer. For those of you who have read my blog, I know there are 5 of you, will know that I've been working on this aspect of server virtualization for some time.  I plan on covering what you should virtualize, how you should do it and how to make dev/test environment better with this solution. So if you want to hear me talk on a great topic, don't forget to register here.

July 23, 2008

1:00 PM Easter

1 hour duration

Daniel

Shipoopi!!

(Homer Simpson Quote of the Blog: "Kids, you tried your best and you failed miserably. The lesson is, never try.")

We are all used to the familiar commands to configure IP Addressing on *nix and *dows types of systems, however there is a little bit of a trick involved with XenServer. 

Imagine if you had built your XenServer in one location and then transported it to another location where a different IP Addressing scheme was being used.  In order to have XenCenter come in contact with the XenServer again, you will need to re-configure the Management IP Address.  Since you probably won't RTM, and you don't want to rip your hair out trying to figure it out, the steps are outlined in this XenServer Tip.

Download this XenTip.

Tap into the power of AppExpert!

The last time I wrote about XenServer and XenApp, I focused on a whole set of items like manageability, availability, flexibility and utilization.  This time, I want to focus directly on utilization as based on the feedback I've received it seems it's the one many people are interested in.

Even before the scalability numbers of XenApp and XenServer came out, I had numerous conversations about virtualizing XenApp.  And now that Citrix is showing the XenServer overhead for virtualizing XenApp, those conversations have increased, but I think some critical points are being lost.  A couple of months ago, Citrix did scalability tests to identify that XenServer has roughly a 7-8% overhead when virtualizing 64-bit XenApp, and roughly 20% when virtualizing 32bit XenApp servers.  I was like WOW, 64bit is great, barely any overhead.  But how many people are actually running a truly 64bit environment?

Most people have the hardware, as it has been sold for years. Most people also have access to the 64bit version of Windows and XenApp. So why aren't we all jumping on the 64bit bandwagon? Because it's the applications. Unfortunately, many applications that XenApp environments run are 32bit, and some are still 16bit!  This conversion to 64bit applications will take time (Does anyone else remember the 16bit versus 32bit migration that happened years ago? It wasn't an overnight thing. It took time. And yet there are still 16bit apps out there.)  So this fact makes it highly unlikely that organizations will be able to convert their XenApp environments into complete 64bit setup. This means many will stay with 32bit only or else have mixed 32/64 bit environments.  So let's focus on the 32bit environments, are they virtualization candidates?

Maybe And most likely Yes.

Take a look at many XenApp deployments and what resource do you typically exhaust first?  RAM.  It is because in Windows 2003, we are limited to 4GB of addressable RAM.  So, when we hit that limit, everything else in the system is wasted (processor, IO and networking).  And I've seen some applications take enormous amounts of RAM. Just the other day I was working on some detailed Visio drawings and Visio took 1GB of RAM.  Yes, I said gigabyte.  (Of course the drawing was about the Simpsons and how Homer stays at the forefront of technology - He even had a blog called "Mr X. - All the Muck That's Fit To Rake").  So, a 20% overhead on 32bit systems? I probably wouldn't notice as my entire server is barely utilized except the RAM.  

RAM is easy to install and one of the cheapest things to add to a server.  Use the same hardware and increase the RAM to at least 8GB.  Now, try to run 2 virtual XenApp servers.  You might not double your user concurrency, but you will get pretty close, which will equate to hardware and power savings.

So take a look at your physical XenApp servers. Is the RAM fully utilized? What about the processor utilization levels?  I bet more likely than not the RAM is fully committed and the processors are running at 10-40% utilization. 

Daniel

(Homer Simpson Quote: "I want to share something with you: The three little sentences that will get you through life. Number 1: Cover for me. Number 2: Oh, good idea, Boss! Number 3: It was like that when I got here.")