My experience using templates in XenServer together with XenDesktop

The other day i was doing a Proof of Concept where i help some ppl building a Citrix environment containing multiples Windows Server 2008R2 servers and some Windows 7 machines. I build 1 VM with Windows Server 2008R2 patched it up to latest hotfixes from MS and then  converted into a template, that i could use as a OS template for my new VM’s i attend to build for VM’s that was needed for a Domain Controller, Citrix Provisioning Server, XenApp Controller, XenDesktop Controller, File server, SQL server well you get the picture.

I build a new domain with some XenApp 6.5 servers, file servers, provisioning, sql, file servers and everything runs smooth and fast off course its new and clean build =O) then when i wanted to build a Citrix XenDesktop Controller the software installed fine and  smooth as it has done multiple times i have build this. When i then wanted to connect to a SQL i got some errors, i troubleshooted it and it seems so weird the SQL issues i had. Well and nice and easy turn was building the SQL express that you can choose within Citrix XenDesktop ISO. I placed the SQL express where i installed the Citrix XenDesktop Controller software. Then lets get things up and running and create and database … new bug.. started to troubleshoot again… hmm. I noticed that all the machines had the same SID that is used when I build them from the template. The solution was building a fresh VM with Windows Server 2008R2, patched it and then install Citrix XenDesktop and then i could connect to the external SQL or to its build-in SQL express if i had chosen that.

I got my lesson learned from Mr. SID.

The case where SID duplication would be an issue is if a distributed application used machine SIDs to uniquely identify computers. And using the machine SID in that way doesn’t work just for the fact that all DC’s have the same machine SID. Citrix XenDesktop relies on unique computer identities either uses computer names or computer Domain SIDs (the SID of the computer accounts in the Domain).

The right way of building a template in XenServer

So the SID really does matter. Prior to taking your clone or image, just remember to use Sysprep as follows:

1) Run Sysprep (on Windows Server 2008 this is located in c:\Windows\System32\Sysprep\Sysprep.exe)
2) Ensure ‘System Out-of-Box Experience (OOBE)’ is selected
3) Tick the ‘Generalize’ option (this resets the SID)
4) Select ‘Shutdown’ from the Shutdown Options.
5) Once the machine has shutdown, take your image and you are good to go!

Good stuff to read about mr. SID

Mark Russinovich explains The Machine SID Duplication Myth (and Why Sysprep Matters)
http://blogs.technet.com/b/markrussinovich/archive/2009/11/03/3291024.aspx

I used PSGetSID from Microsoft Mark Russinovich http://technet.microsoft.com/en-us/sysinternals/bb897417.aspx to see that all my VMs from the template had the same SID.

RES Software have released RES Automation Manager 2012. RES Automation Manager now supports Linux and better integration with Microsoft System Center. In the following article i will describe whats new in RES Automation Manager 2012.

Whats new in RES Automation Manager 2012

RES Automation Manager 2012 introduces the RES Automation Manager Agent for Linux Operating Systems. With this Agent, you can execute the following new RES Automation Manager Tasks on machines running Linux Operating Systems:

• Linux Command (Execute) (“Task “Linux Command (Execute)
• Linux Computer (Reboot, Shutdown) (“Tasks “Linux Computer (Reboot, Shutdown)
• Linux Resource (Download) (“Task “Linux Resource (Download)RES Automation Manager Agents for Linux need to be installed with a separate installation file. The RES Automation Manager Agents for Linux will run on the following Linux Operating Systems:

• Red Hat Enterprise Linux release 4: 4.5 and higher
• Red Hat Enterprise Linux release 5: 5.3 and higher
• SUSE Linux Enterprise Server release 10: versions higher than 10.0
• IBM AIX 5L: version 5.3

Licensing: Evaluation licenses valid for 45 days

When you install RES Automation Manager 2012, 75 evaluation licenses are provided automatically. These evaluation licenses are now valid for 45 days, instead of 60.

New RES Automation Manager Dispatcher: Dispatcher+

RES Automation Manager 2012 introduces a new Dispatcher that has been developed using the latest Microsoft tools. This has enhanced the Dispatcher with the following capabilities:

• Improved scalability: The Dispatcher+ is no longer limited to 150 concurrent connections.
• Native 64-bit installer.
• Resource integrity check: When the Dispatcher+ starts, an integrity check is now performed on the available Resources in the Resource cache of the Dispatcher+. This ensures that Agents can always download valid Resources from the Dispatcher+.
• The availability of a Web API provides full support for building and deploying RESTful and SOAP web services. This allows you to integrate Job scheduling in external systems.
• The Dispatcher+ logs all events in the Event log, which can be viewed with e.g. the Event Viewer that is part of the Microsoft Windows Operating System.The new Dispatcher requires the installation of Microsoft .NET Framework 4 (full version) on all machines hosting a Dispatcher. Please make sure to update all Dispatcher hosts with this version before installing or upgrading to RES Automation Manager 2012

New RES Automation Manager Upgrade Pack

RES Automation Manager 2012 introduces a new Upgrade Pack: the Upgrade Pack now consists of a standalone executable file. This differs from Upgrade Packs of previous releases of RES Automation Manager, in which you could upgrade your RES Automation Manager environment by importing a .WUP file in the Console. The RES Automation Manager 2012 Upgrade Pack can also be used on machines on which no Console has been installed.

As a result of the new Upgrade Pack, the buttons Update Wizard and have been removed from the node Infrastructure > Datastore > Setup > Components in the Console.

If necessary, it is now possible to downgrade to a previous version of RES Automation Manager by right-clicking the node Infrastructure > Datastore > Setup > Components and choosing Downgrade (WUP).

The RES Automation Manager 2012 Upgrade Pack needs to be deployed manually and is not suitable for unattended installations.

RES Automation Manager 2012 upgrade requirements

• RES Automation Manager 2011 SR3 or later
• Microsoft Windows XP SP3 Professional or later (x64/x86)
• Microsoft Windows Installer 3.1
• Microsoft .NET Framework 4.0 or later: Client Profile is the minimum requirement for the machine on which the Upgrade Pack is run; Full Version (Client Profile and Extended) is required for all Dispatchers. Microsoft .NET Framework 4.0 Full Version can be installed on your Dispatchers from the Console.

RES Automation Manager samples for RES Automation Manager 2012

RES Automation Manager introduces a set of samples that make it easier to perform certain IT tasks. These samples are Building Blocks of predefined Modules and include hypervisor Modules, Linux Modules and Microsoft Windows Modules. After importing these Building Blocks into your RES Automation Manager environment, you can adapt the predefined Tasks to your situation if necessary.

The samples are included in the file RES-AM-2012-Samples-6.5.0.0.zip, which can be downloaded from the support portal.

The samples cover the following:

• Linux Tasks:
  • Application Management
  • Disk Management
  • Network Management
  • Security Management
  • Service Management
  • System Management
  • User Management
• Hypervisor Tasks: These Tasks allow you to manage snapshots and VMs on:
  • VMware vSphere Hypervisor
  • Microsoft Hyper-V Server
  • Citrix XenServer
• Additional Tasks:
  • Citrix XenApp 6.5 Unattended Deployment
  • Write Event to Microsoft Windows Event Log

Support for Bare Metal OS deployment using WDS and RES Automation Manager

When deploying new workstations or servers, Bare Metal OS deployment usually is the first task that is performed. This task can now easily be carried out by combining Microsoft Windows Deployment Services (WDS) and RES Automation Manager.

For more information about Microsoft Windows Deployment Services, please refer to the Windows Deployment Services Getting Started Guide, available at http://technet.microsoft.com/en- us/library/cc771670(WS.10).aspx.

For more information about Bare Metal OS deployment using WDS and RES Automation Manager, please refer to the chapter Appendices\Best Practices\Bare Metal OS deployment using WDS and RES Automation Manager of the RES Automation Manager 2012 Administration Guide, available at http://support.ressoftware.com/automationmanageradminguide2012.

Variables

RES Automation Manager 2012 introduces Variables.

When configuring a Task, the values of many fields can now optionally be replaced with Variables. Similar to parameters, Variables function as placeholders for customer-specific values, such as, for example, server names, passwords or credentials. Different from parameters however, Variables are resolved at the moment of Job execution, rather than at the moment of Job scheduling.

The global values of Variables can be set up at Infrastructure > Datastore > Settings > Global Variables. These values are inherited by default by all Teams and Agents, but exceptions for individual Teams and Agents can be set up on the Team’s Team Variables tab and the Agent’s Agent Variables tab.

Team Variables and Agent Variables allow “owners” of a specific Team or Agent to override the Global Variables by specifying a custom-value. This makes Variables especially useful for use in multitenant RES Automation Manager sites, because it makes it easier to manage different settings for different customers and assigned projects, and to exchange Modules, Projects and Run Books with other branches of an organization.

Example

You can set up Global Variables to specify a Domain, Security Context and Domain controller for usage in a Task Manage Active Directory Computer. This creates a generic Task that can be used by all customers in your multitenant site. “Owners” of a specific Team or Agent at the customer site can override the global values of these Variables by specifying a custom-value that only applies to their site. When the Task is executed, the Task automatically gets the correct values that applies to the individual customer site. Depending on the hierarchy of these Variables, these can be the global values, Team-specific values or Agent-specific values.

Video tutorials

As of RES Automation Manager 2012, video tutorials are available that will help you quickly start using RES Automation Manager. These tutorials cover a broad range of subjects, from planning, installing and setting up an environment to using the functionality of RES Automation Manager.

Video tutorials can be accessed from the Help:

Custom Properties from previous versions of RES Automation Manager will automatically be migrated to Variables in RES Automation Manager 2012. Because names of categories in Variables must be unique, any categories in Custom Properties with the same name will be merged into one category in Variables and any existing Custom Properties objects in these categories will be categorized in this category.

A complete list of all available video tutorials by category can be found in the Help, by clicking Help > Video Tutorials from the menu bar of the Console.

Depending on availability, individual tutorials can be accessed from the matching Help topic, by clicking “View tutorial”.

New Tasks in RES Automation Manager 2012

Task “Linux Command (Execute)”

At Repository > Modules, a new Task has been added to the library folder Linux: Execute Linux Commands. With this Task, you can run commands on Agents running on Linux Operating Systems.

Scripts that you run on the RES Automation Manager Agent for Linux using the Task Execute Linux Command cannot include reboot and shutdown commands. Use the Tasks Reboot Linux Computer or Shutdown Linux Computer instead. See Tasks “Linux Computer (Reboot, Shutdown)” (on page 6).

The library Linux and its Tasks will only be available in the Console if your RES Automation Manager environment contains at least one RES Automation Manager Agent for Linux.

Tasks “Linux Computer (Reboot, Shutdown)”

At Repository > Modules, the following Tasks have been added to the library folder Linux: Reboot Linux Computer and Shutdown Linux Computer. With these Tasks, you can reboot or shut down Agents running on Linux Operating Systems automatically. A restart is often required after the installation of new software. These Tasks can also be useful after the execution of a Task Execute Linux Command. See Task “Linux Command (Execute)” (on page 6).

The library Linux and its Tasks will only be available in the Console if your RES Automation Manager environment contains at least one RES Automation Manager Agent for Linux.

Task “Linux Resource (Download)”

At Repository > Modules, a new Task has been added to the library folder Linux: Execute Linux Commands. With this Task, you can download Resources to Agents running on Linux Operating Systems.

The library Linux and its Tasks will only be available in the Console if your RES Automation Manager environment contains at least one RES Automation Manager Agent for Linux.

Tasks “Microsoft System Center Configuration Manager (Distribute Software, Query Client)”

At Repository > Modules, the following Tasks have been added to the library folder Provisioning: Distribute Software with Microsoft System Center Configuration Manager and Query Microsoft System Center Configuration Manager Client. You can find these Tasks in the Task library Provisioning.

Microsoft System Center Configuration Manager allows you to distribute, configure and manage software across virtual, distributed and mobile environments. RES Automation Manager supports Configuration Manager 2007 and 2012.

• With the Task Distribute Software with Microsoft System Center Configuration Manager, you can deploy software distribution packages on Agents on which a Configuration Manager Client is running.
• With the Task Query Microsoft System Center Configuration Manager Client, you can:
  • Create status reports of Configuration Manager clients, including client version, cacheoptions, service states, etc.
  • Obtain an overview of all software distribution packages that were advertised to Configuration Manager clients, including local status of the advertisement, last run date and exit code.

Tasks “RES Automation Manager Job Results (Delete, Export)”

At Repository > Modules, the following Tasks have been added to the library folder RES Automation Manager: Delete RES Automation Manager Job Results and Export RES Automation Manager Job Results.

• With Delete RES Automation Manager Job Results, you can clean up the Datastore from Job results that are no longer relevant, for example because they have become obsolete through Snapshot Intelligence or because they are the results of recurring Jobs.
• With Export RES Automation Manager Job Results, you can export Job results to XML files. This allows you to back up Job results for review purposes. This Task is especially useful in combination with the Task Delete RES Automation Manager Job Results, in which you first back up certain Job results by exporting them to zipped XML files, and then clean up the Datastore by deleting them.In these Tasks, you can delete or export Job results from the Datastore, based on a combination of criteria:
• The type of Job that was performed (recurring/non-recurring)
• The relevance of the Job results (actual Job results/Job results that have become obsoletethrough Snapshot Intelligence)
• The Agent(s)/Team(s) that executed the JobThe period in which the Jobs were executed

Task “RES Automation Manager Team Membership (Change)”

At Repository > Modules, a new Task has been added to the library folder RES Automation Manager: Change RES Automation Manager Team Membership. With this Task, you can add or remove Agents from a Team, and offers a more dynamic way of adding and removing Agents to and from Teams.

This Task is typically used in combination with a Task Query Installed Programs in which an evaluator determines whether the succeeding Task Change Team Membership should be executed.

For example, suppose you want to add an Agent to the Team Office if Microsoft Office is installed on the Agent. You can achieve this by setting up a Module that contains the following:

• A Task Query Installed Programs with an evaluator for Microsoft Office that fails the Query if it does not return results.
• A Task Change RES Automation Manager Team Membership with a condition that executes the Task if the status of the previous Task is Completed. This Task adds the Agent to the Team Office.When the Module is executed, the Agent(s) that execute the Module will be added to the Team Office if Microsoft Office is installed; if not, they will not be added to the Team.

Enhancements and Improvements

Agents: Agents no longer shown as offline when using IBM DB2

When using an IBM DB2 database, all Agents were shown as being offline in the Console. This did not have any consequences for the functioning of these Agents: in reality, they were online and all RES Automation Manager functionality was available. This has been fixed. All online Agents will now also be shown as being online.

Agents: Delete Job history of Agents

At Infrastructure > Agents, it is now possible to delete the entire Job history of individual Agents.

If many snapshots of an Agent are made, for example by using a provisioning server, the Job history of such Agents can become very large and may contain many obsolete entries. In such situations, it can be desirable to clean up the Job history of the Agent.

For this purpose, a button Delete Job History has been added to the History tab of the Agent Properties window, which is available when viewing the properties of an Agent.

It is also possible to delete the Job history of an Agent at Infrastructure > Agents (right-click the Agent, select Delete Job History).

Further informations about RES Automation Manager 2012

For the full release notes read the informations from RES Automation Manager 2012 release notes which can be downloaded from the client portal at www.ressoftware.com

Summary

This article describes how to install XenServer Tools to a custom path by using the command line parameters.

The Windows Para Virtualized drivers are installed by default to C:\Program Files\Citrix\XenTools (or for 64bit Windows C:\Program Files (x86)\Citrix\XenTools ) directory in the virtual machine.

Requirements

Procedure

To install XenServer tools to a custom path by using command line parameters, complete the following tasks:

More Information

CTX130422 – XenServer 6.0 Virtual Machine Installation Guide

Summary

This article describes how to shut down a virtual machine, which is in a pending state (or amber state), from the XenServer control domain.

Requirements

You require the following components:

Background

Sometimes, when you initiate a shutdown or a reboot from the XenCenter, the virtual machine is in an unresponsive state when it is in the pending state (or amber state), and the task being performed is also in an unresponsive state.

The xe-toolstack-restart refreshes all tasks and displays the virtual machine to be in a running state, but the virtual machine would not be available or be responding.

Basically the process(dom-id) associated with the virtual machine is unresponsive in the XenServer control domain. The only method to recover is to terminate the dom-id for the virtual machine or reboot the XenServer.

Procedure

To shut down a virtual machine, which is in an amber state from XenServer control domain, complete the following procedure:

Citrix have released CloudGateway Enterprise for web.

About CloudGateway Enterprise

CloudGateway Enterprise is designed to offer a single point of control for enterprise delivery of Windows, Web and SaaS applications, with a seamless end-user experience across the various Receiver variants. CloudGateway Enterprise comprises of three key components:

1. StoreFront services- The Windows component allowing the various Citrix Receivers to connect to the enterprise store, and deliver Windows, Web and SaaS applications to users, with a follow-me subscription and launch experience.
2. AppController- A linux based virtual machine available for both XenServer and vmware based hosts, providing the central administrative point for configuration of all enterprise Web and SaaS applications, to be delivered to end users, with a single sign-on federation and consolidated provisioning capabilities
3. Gateway services – Delivered through the Access Gateway component, either standalone, or as a feature of the NetScaler MPX, VPX and SDX platforms.

Note that CloudGateway Enterprise provides the license entitlement for the Access Gateway universal licenses, but the actual AG physical or virtual appliances actually needed to deploy this functionality, will need to be procured independently

In addition to the above components CloudGateway Enterprise will also consist of regular AppConnector update packs, which will include new connectors for applications, that will keep increasing the number of applications supported for both federation and user account provisioning support within the AppController.

Source

Download Citrix CloudGateway Enterprise here

My knowledge with Citrix XenDesktop 4/5.5 HDX 3D Pro and Multiple screens, desired resolution.

I was about to write an article about how to configure a desired screen resolution or if you have multiple screens and you wanted this to work, when you connect your Citrix Receiver to your Citrix XenDesktop 5.5 HDX 3D Pro Virtual Desktop. Citrix support have been so kind and created this knowledge article on how to configure a desired screen resolution or if you have multiple screens.

I have been aware of this solution since Citrix XenDesktop 5.5 HDX 3D Pro was released but i havent shared this with you, sorry for the delay.

But i will share some thoughts that you should be aware of, my knowledge is based from field experience with HDX 3D Pro.

Hint 1:
I recommend that you export EDID informations from the endpoint device that you use Citrix Receiver to connect to your Citrix XenDesktop 5.5 HDX 3D Pro VDI.
This EDID file is the one you apply on your host machine where Citrix VDA 5.5 is installed with HDX 3D Pro.

If your end device have 2 Monitors where 1 is DVI input and the other is VGA input. I recommend that you take the best input (DVI) export the EDID and import this file on the VGA monitor on the end device and then you import the EDID configuration on the host machine where  Citrix VDA 5.5 is installed with HDX 3D Pro.

Hint 2:
If you experience issues with mouse cursor is not in sync on the session after you have imported the EDID file(s) i recommend that you disconnect the HDX session and reconnect to get the new screen informations that you have applied with EDID configuration.

Hint 3:
You should be aware that when you create virtual screens with EDID and attach multiple screens the user consumes more bandwidth. This is also the behavior with a higher screen resolution.

Hint 4:
You can use EDID fix with Citrix XenDesktop 4 HDX 3D Pro =O) it works with Windows 7 / Windows XP

How to Get the Desired Desktop Resolution and Configure Multi-Monitor in case of HDX 3D Pro Enabled Desktop in XenDesktop 5.5

Summary

This article describes how to get the desired desktop resolution and configure Multi-monitor in case of HDX 3D Pro enabled Desktop in XenDesktop 5.5.

Supported Desktop Resolution with HDX 3D Pro in XenDesktop 5.5

Multi-Monitor Configuration

Configuring Virtual Monitors

Virtual monitors can be configured for VDA on physical machine with NVIDIA GPU and for Virtual Machine on XenServer 6 with NVIDIA GPU assigned to it. Following procedure explains how to add multiple virtual monitors:

Step 1: Getting Monitor EDID Files

Complete the following procedure to get Monitor EDID file:

Note: In some cases, the EDID file exported from monitor connected using DVI connector can be used only for DVI ports to create virtual monitors. Same applies for other ports, for example the Display port. So it is recommended to use the matching EDID file only.

These EDID files are created for the following specifications:

Monitor: HP LP2475w

GPU: NVIDIA Quadro 5000

Maximum Resolution: 1920×1200

Refresh rate: 60 Hz

If the requirement is similar to the preceding requirement then the following EDID files can be directly used:

Step 2: Importing EDID File to Create Virtual Monitor

Once the EDID file is available, it can be used to create the virtual monitors.

Complete the following procedure to import the EDID file in the NVIDIA control panel:

Note: This way by creating virtual monitors on VDA (Physical Machine or Virtual Machine), HDX 3D Pro desktop can be used in multi-monitor mode.

Summary

This article lists the hardware used by Citrix to test the HDX 3D Pro feature for the August, 2011 release of XenDesktop 5.5. It is intended that this article provide guidance for customers when choosing hardware to be used with HDX 3D Pro and XenDesktop 5.5. Note that this is not an exhaustive list of all the hardware that can be used with HDX 3D Pro, just a list of the hardware that was specifically used for testing by Citrix Engineering. Other hardware not listed below that meets the system requirements for HDX 3D Pro may also be used.

Graphics Processing Units

Based on the testing carried out by Citrix, most NVIDIA Quadro and Quadro FX graphics cards should work in standalone mode with HDX 3D Pro. Citrix has tested only a few NVIDIA Tesla and GeForce graphics cards. Although it is expected that these classes of graphics cards will work, Citrix recommends that you carry out your own testing before putting such graphics cards into a production environment.

Although Citrix has only tested a few ATI-AMD graphics cards, it is expected that they will work with CPU-based compression.

Hardware for Application Host and User Device

The hardware requirements for both the computers hosting the graphical application (along with the HDX 3D Pro Virtual Desktop Agent) and the devices from which users access the host are given in the System Requirements for HDX 3D Pro[http://support.citrix.com/proddocs/topic/xendesktop-als/hd-3d-sys-req.html]. Any hardware that matches these specifications can be used. Citrix tested the HDX 3D Pro feature using the following hardware.

The following machines were used as endpoints for testing.

Monitors Used for Testing

There are no restrictions on the monitors that can be attached to the user device and the computer hosting the graphical application, provided that they support the required resolution. Citrix used the following monitors for testing.

Tested 3D Mice

Citrix used the following 3D mice for testing.

About Citrix XenConvert

Citrix XenConvert is a physical-to-virtual (P2V) conversion tool for converting a Windows operating system, applications, and data from a physical machine to a XenServer virtual machine, Provisioning Services vDisk, virtual appliance in the Open Virtualization Format (OVF), or disk image in the Virtual Hard Disk format.

XenConvert 2.4. adds the following improvements :

• XenServer 6.0 support
• Provisioning Services 6.0 support
• Select target storage repositories during conversion
• Copy files in use during Windows Server 2003 conversions

XenConvert 2.4.1 fixes the following issues :

• XenConvert does not duplicate the compression state of a directory
• XenConvert does not restore the original owner of select system files owned by a system service with privileges greater than the local administrator
• XenConvert allows the choice of invalid storage repositories when converting to XenServer
• XenConvert virtual-to-virtual (V2V) functionality is now included in XenCenter and complements the new virtual appliance and disk image import feature in XenServer 6.0.Use XenCenter 6.0 to import virtual appliances and disks created by XenConvert.

Download Citrix XenConvert 2.4.1 here (require MyCitrix ID)

Summary

This article describes how to improve network performance in XenServer Feature Pack 1 Virtual Machines (VMs) by using a Network Interface Card (NIC) with Single Root I/O Virtualization (SR-IOV) support. Customers running XenServer 6.0 should refer to CTX131381 – How to Assign SR-IOV Enabled NICs with XenServer 6.0

Background

The SRIOV support is a method used for sharing I/O devices with near physical computer speed.

To learn more about SR-IOV, refer to PCI-SIG SR_IOV Primer.

Note 1:  A single SR-IOV NIC can support multiple Virtual Functions; each Virtual Function can be attached to a different VM as a 1:1 ratio (1 Virtual Function to 1 VM).

Note 2:  Xen Kernel version 3.4.2 supports the SR-IOV features for Red Hat Enterprise Linux or SUSE Linux Enterprise Server.  Citrix XenServer 5.5 however does not support it.

Note 3:  Citrix only has one NIC certified for SR-IOV on XenServer Feature Pack 1 (Intel 82599 10 gigabyte Ethernet Controller).

Procedure

Perform the following the steps to enable SR-IOV on XenServer Feature Pack 1.

More Information

CTX126624 – XenServer Single Route I/O Virtualization (SR-IOV) Support for Provisioning Services Virtual Machines

CTX131381 – How to Assign SR-IOV Enabled NICs with XenServer 6.0

Summary

This article contains guidelines that should be considered when  connecting XenServer to a switch:

Requirements

You require Administrative access to the switch.

Background

Switch ports must be configured differently for a XenServer host as opposed to a standard workstation. The following considerations are recommended when connecting a XenServer to a switch.

Considerations

Change the following options on the switches for XenServer ports: