I had some really great questions based on the TechTalk of “Simplifying the Migration to XenApp 5 with XenServer”.  Many of the questions focused on the actual aspects of using Provisioning Server. As many of you are unfamiliar with the solution, i created a video that would help you better see what this solution can do for you.  Hopefully, the video will help answer your questions.  

Watch this Video to see how Provisioning Server delivers XenApp

Also, if you want to replay the TechTalk, you can access it from here.

During the TechTalk, i mentioned a few white papers that were created focused specifically on this topic. Click on the item for the doc.

Q: I didn’t understand how you take an existing server and turn it into a virtual server?

A: You have to reinstall the physical server with XenServer. After that, you can provision new virtual XenApp servers. The XenServer install takes 10 minutes(very easy) and streaming a new XenApp server takes about 30 seconds, which is the server boot time.  

Q: After a server is provisioned with the OS, how can it be automated to install/setup Citrix and then publish apps ? Are these manual steps ?

A: The provisioned server is completely configured.  It will have XenApp and the applications installed.  The XenApp integration utility for Provisioning Server takes care of all of the lower-level changes to add the new provisioned servers to the XenApp farm.  The only thing you have to do for a newly provisioned server is to publish the applications on the server. 

Q: How can Citrix XenServer or Provisioning handle differences in hardware when deploying ?”

A: XenServer is a virtualization layer sitting between the hardware and the operating system.  The provisioned, virtual XenApp servers will use the XenServer drivers.  This means a single driver, the XenServer driver, can be used across a wide range of different physical hardware.  

Q: Can you run XenApp 5 on Windows 2003 Server environment?

A: Yes, the same process explained within the TechTalk can also be used for XenApp 5 on Windows 2003. Actually, this process can be used for future versions of XenApp.

Q: Will the XenApp run on a VMware environment?  We currently use VMWare.”

A: Yes. It will run on VMWare ESX and also on Microsoft Hyper-V.  However, I would recommend you take a look at performance results from INDEPENDENT tests.  XenServer was optimized for XenApp workloads. As you are very aware, XenApp is very unique in that many users are physically on the XenApp servers, which causes huge spikes in context switches due to the sheer number of applications and processes running.  To get the best performance, you need a server virtualization solution that understands the workload and adjusts accordingly.  This is done by a single configuration option in XenServer.  I’m concerned that if you simply select VMWare because you already use it for other workloads that you will be very disappointed in the results and turn away from the benefits of virtualization. I encourage you to take a look at these items:

Q: Does vDisk support multiple drives?  C:\ and D:\ or just the system drive?

A: Yes

Q: Explain the drag and drop of published apps…Example. Does this install the published apps?

A: Depends.  If you are using streamed applications on the XenApp server, it will.  If you are using installed applications it won’t.  However, I’d recommend that your base vDisk image from Provisioning Server contains the installed applications.  That way, when you provision servers, you can go into the management console and drag the published application onto the new server.  So if you have a XenApp farm with 3 different silos of XenApp servers, based on the applications they host, you will probably want to have 3 different Provisioning Server vDisks (images).

Q: How do you determine the MAC address for the Virtual server? how do you avoid existing MAC address of other hardware address.

A: Within the XenCenter console, you can see the MAC address for each virtual server without being required to go into the virtual server’s console.  It shows up in the networking tab. 

Q: If we upgrade to XenApp5 will the version 10 of the Citrix client still work? 

A: Yes, but the users will not be able to utilize new XenApp features that require a newer client. 

Q: If your vdisk Image on the provisioning server is taken from the test server, how does it get a new name and IP information each time it is applied to a different VM server?

A: This is the magic of Provisioning Server. This got me when I first was introduced to Provisioning Server.  It uses the target device name  you create within the Provisioning Server console.  The provisioned image will use that name. That name will also be in Active Directory with full membership in the domain.  As for IP, that is all via DHCP.  If you want your provisioned servers to have static IP addresses, you can create reservations within the DHCP based on the MAC address.

Q: Is there a way to Provision actual XenServer?

A: Not at this time. 

Q: It is very disappointing that you are not addressing the client portion of conversions and that you advocate including applications in the base images. I know that you believe that clients are not impacted, but the reality is that that is not the case. Until you figure out a way to address the server hardware dependencies, the required client coordination, and the inability to layer applications automatically after the base image, I don’t expect to be able to migrate to a new version without it taking months. It’s also highly unrealistic to expect that we could upgrade our environment without having a dual-version environment.

A: I’m not sure I understand this question.  During the migration, you will most likely have two versions running at the same time.  You need to use Web Interface to enumerate applications from both farms.  Recommended that you migrate entire XenApp silo’s over at once.  If you can’t do that, then you need to have applications in one farm published to some users and the same applications in another farm published to the other users. That way you have enough resources in both farms.

As for the including applications in the base image, that is really based on the application.  If you can use XenApp Application Streaming, then you don’t have to include the applications in the base image.  A XenApp image, with no applications could take on any role you wanted and host any application you wanted just by publishing the appropriate applications.

Q: Regarding the cloning, does XenServer take care of the post clone steps for XenApp and also does it modify the servers’ SID to prevent duplicate SID’s in the environment

A: Yes, as long as you setup your VM Template correctly.  Cloning is a complete duplicate of the original. If your template VM that you will use for cloning is setup in a SysPrep’ed state, then all clones from it will have a new SID, name and identity.  However, using Provisioning Server, you don’t use the SysPrep-type utility. Provisioning Server changes the server’s identity based on the name you specify in the Provisioning Server console.

Q: am I correct in thinking that XenApp has its own VM and does not ‘sit’ on a separate VM product (like VMWare)? 

A: XenApp would sit on a separate product that is called XenServer.  However, because XenServer and XenApp are owned by Citrix, great lengths have been gone into making sure you get the best performance possible, and that it is as easy as clicking a button.

Q: We’re already doing this with VMWare VMs. Are there any advantages to switching to XenServer VMs? (Especially performance / ease of management improvements.) We’re currently running ESX 3.5 and XenApp 4.5; we’re definitely upgrading to XenApp 5.0 (in process) and considering switching to XenServer.

A: I strongly encourage you to take a look at these items.  In ages past, I would not have recommended virtualizing XenApp because the performance hit was too great, basically you are throwing hardware away.  However, that changed in XenServer 4.1.  XenServer has a special optimization setting for XenApp workloads that greatly improves performance.  Take a look at the following for more information (some are from independent, non-Citrix, sources):

Q: What about the server name being the same as the image.

A: Provisioning Server will use the target device name you enter in the Provisioning Server console. Each server will then have different identities. 

Q: When is Dan coming back to Cleveland to buy more Chinese food?

A: LOL, I all of the sudden have a huge craving for it.

Q: Does all the “”automation”” require Workflow Studio? If not, what value does WFS bring above what’s part of provisioning server?

A: No, Workflow Studio is not required or used on any of the items I spoke about. Think of Workflow Studio as a way to automate tasks that you have to do on schedule (like server reboots) or when a trigger is hit (like if the load on a silo of XenApp servers is too high to spin up a new XenApp server).  That being said, you can automate just about anything, you just need to decide if the time required to build your workflows will save you time in the long-run. 

Q: Does dynamic VHD resizing negatively impact performance of the target server?”

A: Yes and No. I love answers like that.  First, it will because you have to keep expanding the disk and that takes resources.  But no because when the vDisk is in production, it is in a read-only mode (Private image). That means changes are not kept within the vDisk, so the vDisk will not expand. 

Q: Where and how are all the parameters for the specific machine stored: machine name, domain name and SID, domain password of the domain machine, etc.

A: Provisioning Server takes care of it. The name is based on the target device name you set in Provisioning Server, which is kept in the Provisioning Server database. The domain information is also configured in the Provisioning Server Console. Provisioning Server also maintains and manages the machine’s password and keeps it updated with Active Directory.