Category: Unidesk

App Layering – App Layers, Image Templates, and Publishing

Last Modified: Sep 27, 2023 @ 7:22 pm

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Change Log

Create App Layer

Note: Citrix App Layering does not isolate applications. If you need isolation (e.g. multiple versions of Java), consider implementing Microsoft App-V. Citrix App Layering merges the layers without isolation.

  1. See Citrix CTX225952 4.x Layering Best Practices
  2. In the ELM Management Console, go to the Layers tab or node.
  3. In the App Layers tab, click the Create App Layer button. Or in the Silverlight interface, right-click in the grey, and click Create App Layer.

  4. In the Layer Details page, give the layer a name and version. Since the App Layer is tied to the OS Layer, it’s a good idea to include the OS Layer name in the App Layer name.
  5. Give the layer a Max Size. If Offload Compositing is not enabled then the layer disk created for the vSphere Packaging Machine is Thick Provisioned. Scroll down or click the down arrow.

  6. In the OS Layer section, select an OS Layer and version. An App Layer created for one OS Layer cannot be used with another OS Layer. Scroll down or click the down arrow.

  7. In the Prerequisite Layers section, you can select additional dependent App Layers to include in your packaging machine. If there are no dependent layers, just scroll down or click the down arrow.

  8. In Silverlight, in the Connector page, select a vSphere connector, and click the down arrow.
  9. In the Platform Layer section, if you are creating the App Layer on a different hypervisor than originally used for the OS Layer, you can select the Platform Layer for the new hypervisor. If the hypervisor has not changed, just scroll down or click the down arrow. The hypervisor can also be changed when publishing the Image Template later.

  10. In the HTML5 interface, select a Connector, enter a filename for the .vmdk file, and click Confirm and Complete.

    1. In the Silverlight interface, in the Packaging Disk page, give the .vmdk file a name, and click the down arrow.
    2. In the Icon Assignment page, select an icon, or upload a new one, and click the down arrow.
    3. In the Confirm and Complete page, click Create Layer.
  11. Go to the Tasks page. Or in Silverlight, at the bottom of the page, open the Tasks panel.
  12. Click View Details for the running task. Or in Silverlight, click the information icon next to the running task.

  13. Eventually the task will finish deploying the Packaging Machine and say Action Required.

  14. In vSphere Web Client, find the new Packaging Machine (in the PackagingVMs folder in the Layering VM folder), open its console, and install your app normally.
  15. See App layer recipes at Citrix Docs for some application install instructions.
  16. Citrix CTX226984 App Layering/Unidesk: The list of Windows Updates is usually wrong in app/platform layers and published images/desktops.
  17. Antivirus can be installed on an App layer. See Deploy anti-virus software at Citrix Docs for instructions for the following:
    • Symantec
    • McAfee
    • Trend Micro
    • Sophos
    • AVG
    • Kaspersky
  18. User settings are not captured in an Application Layer.
  19. Domain Join – CTX224668 How to install applications that require joining the domain with Citrix App Layering – In summary, you can join a layer to the domain while packaging, but you must remove it from that domain before finalization.
  20. For Office, put all Office apps in one layer.
    • Print to OneNote does not work in Elastic Layers.
  21. For Office 365 Click-to-run activation:
    1. After Office Click-to-run is installed, for all OSs other than Windows 7, run C:\Windows\Setup\scripts\Office2013Windows81_PREP.cmd as Administrator.
    2. In App Layering 4.6, Optimize.hta and Office Activate.cmd can handle Office 365 Click-to-run activation. For 4.5 and older, see Rob Zylowski at Office Activation Scripts for Office 365 at Citrix Discussions, to download these scripts . Also see O365 Office 2016 click to run online activation at Citrix Discussions.
    3. Go to C:\Windows\Setup\Scripts, right-click RunOptimizer.cmd, and click Run as administrator.
    4. Scroll down to J, check the box next to Process Office 365, and click Save Settings A-K.
    5. This creates a file called ProcessOffice365.txt.
    6. See Citrix CTX224566 Unidesk Recipe for Office 2016: Using Shared Computer Activation From Office 365 for more licensing guidance.
  22. For Office Volume License activation: (Source = Citrix CTX224900 Windows / Office 2016 KMS not activating in App Layering images (MCS Image Prep OS Rearm Failed)
    1. Go to C:\Windows\Setup\Scripts, right-click RunOptimizer.cmd, and click Run as administrator.
    2. Configure item H.
    3. Scroll down a little bit and click the button labelled Save Settings A-K. Then click the Optimizer.


    4. For all OSs other than Windows 7, run C:\Windows\Setup\scripts\Office2013Windows81_PREP.cmd as Administrator.
    5. Then rearm Office by running C:\Program Files\Microsoft Office\Office16\OSPPREAM.exe as administrator.
  23. When you are done installing your app, finalize the layer:
    1. George Spiers Citrix App Layering Preparation Script: runs a number of tasks to clean out temporary folders, clear out Event Log entries, remove ghost devices from Device Manager, etc.  ?
    2. Double-click the Shutdown for Finalize icon on the desktop. If it finds issues, it will tell you what to do (e.g. reboot needed). Otherwise, it will shut down the VM.
  24. If Offload Compositing is enabled in your Connector, then upload will happen automatically.
    1. Otherwise, after the machine is shutdown, in ELM Management Console, go to Layers > App Layers.
    2. Right-click the Layer that is currently being Edited, and click Finalize.
    3. In the Script Path page, if you embedded any scripts in the layer, specify the path. Otherwise, just click the down arrow.
    4. In the Confirm and Complete page, click Finalize.
  25. It will eventually finish and say Deployable.

  26. You can Edit Properties on your App Layer to change the icon or specify a Script Path.

Windows Updates – From Gunther Anderson: “Generally, the list of updates is unreliable anywhere except the layer where the updates were installed. If your OS layer says the updates were installed, then they were. The actual list (the list is not the same as the actual updates) tends to get stepped on by your other app layers, since they remember the updates list from when they were originally created. With all of your app layers trying to set their own personal misunderstanding based on when they were initially created, what winds up in the published image is not a good reflection of any reality. However, the information from the OS layer is correct. Likewise, the list of Office updates shown in the Office layer is correct even when the list of Windows updates shown in the Office layer is not.”

User Layer Repair – App Layering 1908 and newer create User Layer Repair files for any new or edited App Layer. Uses these files to repair User Layers so that the App Layer you just created or edited overrides the User Layer.

Citrix has a User Layer Management Utility that does more than just repair. It can also Reset (rename) user layers, Compress them, or Expand them. This tool also works with FSLogix disks.

To repair user layers without using a utility:

  1. Find the repair files in your file share under \Unidesk\Layers\App\Repair and \Unidesk\Layers\App\PackageAppRules.
  2. Copy the UserLayerRepair.json file for the App Layer to the user’s User Layer .vhd location.
  3. Make sure Domain Computers has Modify access to the user’s VHD location. The repair function runs as the computer, not the user.
  4. After logging into a published machine, C:\Programdata\Unidesk\Logs\ulayersvc.log shows the Repair status.

OS Layer Switching – if you enabled the OS Layer Switching Lab Feature, then do the following:

  1. Edit Properties on the App Layer.

  2. In the App Layer Settings section (Layer Details page) is a checkbox to Allow this App Layer to be elastically assigned to all Layered images, regardless of OS layer (Allow OS Layering Switching). You’ll need to repeat this for each additional App Layer. Source = Elastic layers to other OS layers not working as expected at Citrix Discussions.

Image/Template

  1. In the ELM Management Console, go to the Images node/tab, and click Create Template.
  2. In the Name and Description page, give the Template a Name that indicates the OS Layer, Platform Layer, and App Layers. Then scroll down or click the down arrow.
  3. In the OS Layer section, select an OS Layer, and scroll down or click the down arrow.
  4. In the App Layers section (Application Assignment page), click Edit Selection and select zero or more applications. Any App Layer you select here will be merged into the machine pre-boot. Elastic Layers are assigned later. Click the down arrow.

  5. In HTML5, in the Platform Layer section, select a Platform Layer and version. If you are pushing to PVS, then make sure the Platform Layer includes the PVS Target Device Software. Scroll down.
  6. In HTML5, in the Connector section, select an existing Connector. In the HTML5 interface, in App Layering 2202 or newer, use the Connectors page in the HTML5 interface to add a Provisioning Services connector. Or use the Internet Explorer Silverlight interface at System > Connectors. See below for some configuration info for this type of Connector.
  7. In the Layered Image Disk page, give the .vmdk file a name, specify a size, and decide if you want Sysprep to run or not. You typically don’t need to Sysprep the image if you’re using MCS, PVS, Composer, or Instant Clone.
  8. App Layering 2308 and newer have an option to Defragment Layered Image Disk.
  9. If you wish to enable Elastic Layering, select it here to enable it in the Image Template. Assignment of Elastic Layers to users is described later. Notes:

    • Disk Free Space – when you enable Elastic Layering, the published image only gets 20 GB of free space due to the addition of a writable partition. To change the size, see CTX225030 How to set the default size of the Elastic Layering writable volume. You edit /usr/local/CAMService/CAMService.exe.config and add the line <add key="ScratchVolumeSizeInMB" value="20480"/>
    • Login time delay – From Rob Zylowski at XenApp Image Template Application Assignment vs Elastic Delay at Citrix Discussions: “There is a 5-8 second penalty just for turning on elastic layering. But its not a straight x seconds per app because the mounts run in parallel. However more apps do take longer. What can have more of an effect is if the app has a service. We have to mount the disk, read it and then start the service before we allow the logon to ensure that the service is available if your logon actually needs it. There is a log at c:\programdata\unidesk\logs that will tell you the time associated with mounting and starting elastic layers so you will know how much of the logon impact is due to elastic layering.”
    • Elastic Layers Path Override – The path to Elastic Layers can be overridden by setting HKEY_LOCAL_MACHINE\SOFTWARE\Unidesk\ULayer:RepositoryPath on the published machine. See CTX222107 You can change the Elastic Layer repository in the registry without reimaging (4.x).
    • Citrix Profile Streaming Compatibility – App Layering 4.12 and newer support Citrix Profile Management Profile Streaming with Elastic Layers. Also see Elastic Layers and Profile issues at Citrix Discussions.
    • Delayed loading – By default, Elastically Assigned Layers are loaded at the end of the login process so that the user can get to a desktop quickly and not have to wait for their Elastic Layers to surface first. However, especially with Session Hosts, you may find that the Elastic Layers are not available quickly enough. It is possible to make Elastically Assigned Layers attach at the beginning of the login process. by setting HKLM\SOFTWARE\Unidesk\ULayer\MaxCompositingPhase = 0. More info at CTX246468 How to disable delayed loading of Elastic Layers on an image.
  10. User Layers is another option. Notes:

    1. User Layers have the same application compatibility limitations as Elastic Layers.
    2. Storage Locations for User Layers are configured at System > Storage Locations.
      • In App Layering 2005 and newer, you can set a custom path by creating a REG_SZ value called CustomUserLayerPath in the HKLM\Software\Unidesk\Ulayer key. See How to specify a custom user layer path at Citrix Docs.
    3. The default size for User Layers is 10 GB. You can change this size by setting HKLM\Software\Unidesk\Ulayer\DefaultUserLayerSizeInGb on the managed machines. Source = Understanding Elastic Layering > Scaling (tab) > User Layer Size.
    4. Multiple access to the User Layer VHD is not allowed.
    5. After logging into a published, layered machine and mounting a user layer, you must revert the machine. Non-persistent Catalogs automatically revert the machine after logoff. Or take a snapshot before logging in and revert to snapshot after logging out.
    6. David Wilkinson describes User Layers in detail at Citrix Application Layering – User layers.
  11. Office 365 User Layers is a fully supported feature. For details (including limitations), see:

  12. Session Office 365 User Layers can roam Outlook OST files on RDSH VDAs.

  13. Scroll down or click the down arrow and then click the Confirm and Complete button or Create Template button.
  14. The Image is then displayed as Publishable.

Clone Template

There’s a Clone Template feature to more easily create multiple templates with similar configurations.

  1. On the Images tab, select an existing Image Template and click the Clone button.
  2. Right-click the newly created template and click Edit.
  3. Notice the name has – Copy on the end. Feel free to change the name and edit the new template as desired.

Publish Image

  1. Select a publishable image template and click Publish Layered Image.
  2. In the Confirm and Complete page, click Publish Layered Image.
  3. Open the Tasks pane and click View Details (the information icon) to view details of the running task.
  4. If publishing to MCS (vSphere):
    1. In the vSphere Web Client, you’ll find the Template VM under the TemplateVMs folder under the Virtual Machine folder you selected for the Connector.
    2. Citrix MCS creates VMs in the same Folder as the Master Image. You might want to move the Template VM to a different virtual machine folder.
    3. For MCS, in Citrix Studio, create a Machine Catalog using the Template VM as the Master Image.

    4. Notice that MCS creates VMs in the same Virtual Machine folder as the Master Image.
  5. If publishing to Provisioning Services (PVS):
    1. The image is uploaded to the vDisk Store as a .VHD file (not .VHDX).
    2. And it’s automatically added to the vDisk Store in the PVS Console. You can now assign it to your Target Devices.
    3. You can Redirect ulayersvc.log to another folder or drive by modifying C:\Program Files\Unidesk\Layering Services\ULayer.exe.config. You can only modify this file after the image is published. (Source =CTX237138 Redirect ulayersvc.log to another folder or drive)
    4. CTX226065 Citrix App Layering 4.x: PVS Image Management – choose an image, then list all the targets using that image optionally filtering on one ore more collections, then “promote” the image to all selected targets.
    5. If the PVS Image prompts for a reboot, then see CTX230767 App Layering: Published image to PVS prompts user to restart computer. Create a new Platform Layer version. Take an existing Write Cache disk and attach to the Packaging VM so it can detect the new hardware. Remove the second disk and Finalize the Layer.

Elastic Layers

Logon delay – From Rob Zylowski at XenApp Image Template Application Assignment vs Elastic Delay at Citrix Discussions: “There is a 5-8 second penalty just for turning on elastic layering. But its not a straight x seconds per app because the mounts run in parallel. However more apps do take longer. What can have more of an effect is if the app has a service. We have to mount the disk, read it and then start the service before we allow the logon to ensure that the service is available if your logon actually needs it. There is a log at c:\programdata\unidesk\logs that will tell you the time associated with mounting and starting elastic layers so you will know how much of the logon impact is due to elastic layering.”

Citrix.com Understanding Elastic Layering – A technical overview of the Citrix App Layering 4.x Elastic Layering Architecture and Configuration details

Provisioning Cache Disks – Citrix CTX227454 App Layering: PVS Cache Disks May Need to Be Larger with Elastic Layering: you may need to add capacity to your Cache Disks and/or Cache Memory reservation on your Target Machines to support App Layering with Elastic Layers. App Layering caches entire modified files, not individual modified blocks.

Profile Streaming Compatibility – App Layering 4.12 adds support for Citrix Profile Management Profile Streaming with Elastic Layers. Also see Elastic Layers and Profile issues at Citrix Discussions.

Delayed loading – By default, Elastically Assigned Layers are loaded at the end of the login process so that the user can get to a desktop quickly and not have to wait for their Elastic Layers to surface first. However, especially with Session Hosts, you may find that the Elastic Layers are not available quickly enough. It is possible to make Elastically Assigned Layers attach at the beginning of the login process. by setting HKLM\SOFTWARE\Unidesk\ULayer\MaxCompositingPhase = 0. More info at CTX246468 How to disable delayed loading of Elastic Layers on an image. 💡

To assign elastic layers to users:

  1. In HTML5, select an App Layer and switch to the Version Information tab. Select a version and click Update Assignments.

    1. In Silverlight, go to Layers > App Layers. Right-click a Deployable App Layer, and click Add Assignments.
    2. In the Select Version page, select an App Layer version, and click the down arrow.
    3. In the Image Template Assignment page, don’t select anything. This page lets you assign this App Layer to a Image Template for pre-boot merging. For Elastic merging/mounting, just click the down arrow.
    4. In the Elastic Assignment page, note any issues that Elastic Fit discovered that would prevent the app from merging elastically correctly. If you’re OK with the issues, click the Assign Elastically button.
  2. In HTML5, switch to the Elastic Assignments tab and click Assign to new users.
  3. Search for a user group you want to assign this Layer to, and check the box next to the group. Click Save when done. Or click the down arrow when done.

  4. Click Confirm and Complete. Or in Silverlight’s Confirm and Complete page, click Assign Layer.

  5. Open the Tasks pane to see the progress while it copies the App Layer to the remote SMB share.

  6. When it’s done, go to the SMB share to see the files it uploaded, including the .json files that contain Layer assignments.
  7. To enable Elastic Layers in machines created from a ELM Image Template, edit the Template (Images), and make sure Elastic Layers is enabled in the Layered Image Disk page.

  8. Note: when you enable Elastic Layering, the published image only gets 20 GB of free space due to the addition of a writable partition. HTML5 lets you edit the size of this writable partition.

  9. If you find that App Layers are conflicting with each other, you can adjust the App Layer priority by using the Unidesk 4 Layer Priority Utility — Experimental tool.
  10. From Citrix Discussions Application from an Elastic Layer as “Published App”? You can publish an elastic app. Simply publish an app, but manually specify the path to where executable would be. The app is mounted before the user logs in, so it will be there when Citrix tries to launch the app.
  11. The path to Elastic Layers can be overridden by setting HKEY_LOCAL_MACHINE\SOFTWARE\Unidesk\ULayer:RepositoryPath on the published machine. See CTX222107 You can change the Elastic Layer repository in the registry without reimaging (4.x).
  12. To debug Elastic Layers, see CTX222133 Elastic Layering Logs. Only Info logging is enabled by default.
    1. In C:\Program Files\Unidesk\Layering Services\ulayer.exe.config, set LogFileAppender level to Debug
      1. Must be set before machine boots.
    2. C:\ProgramData\Unidesk\Logs\ulayersvc.log

Update Layers

  1. You can optionally select an existing App Layer and click Clone. You would do this if want to create a new branch of app updates without affecting the main branch.

    1. You can select a particular version of the source layer.

    2. It takes a bit of time to clone the layer. Use the Task status panel to see when it’s done.

  2. In the HTML5 interface, select an App Layer, switch to the Version Information page, and then click Add Version. In Silverlight, right-click an App Layer and click Add Version.

  3. In the Version Details page, enter a new version, and scroll down or click the down arrow.

  4. In the OS Layer page, click the down arrow.
  5. In the Prerequisites Layers page, click the down arrow.
  6. In the Connector page, select a Connector, and click Confirm and Complete, or click the down arrow.

  7. In the Platform Layer page, click the down arrow.
  8. In the Packaging Disk page, click the down arrow.
  9. In the Confirm and Complete page, click Add Version.
  10. The task details shows the current progress.
  11. It eventually says Action Required.
  12. When the Packaging Machine is deployed, you can connect to its console and perform any desired updates. When you are done performing updates, finalize the layer:
    1. George Spiers Citrix App Layering Preparation Script: runs a number of tasks to clean out temporary folders, clear out Event Log entries, remove ghost devices from Device Manager, etc.  ?
    2. Double-click the Shutdown for Finalize icon on the desktop. If it finds issues, it will tell you what to do (e.g. reboot needed). Otherwise, it will shut down the VM.
  13. If Offload Compositing is enabled, then upload happens automatically.
    1. Otherwise, when done updating the Packaging Machine, right-click the App Layer that is marked as Editing, and click Finalize.
    2. In the Script Path page, click the down arrow.
    3. In the Confirm and Complete page, click Finalize.
  14. View the task details to see the current progress.

  15. To confirm that you have a new version, in HTML5 interface, select the App Layering and switch to the Version Information tab. In Silverlight, right-click the App Layer, and click Delete Versions.

  16. You can only delete versions that are not assigned to any Image.

  17. There are two methods of assigning a new version: one image at a time, or multiple images.
  18. To edit one image:
    1. Go to the Images tab. Select an Image, and click Edit Template.

    2. In HTML5 interface, scroll down to the App Layers section and click Edit Selection. Select the new version and click Save. Then click Confirm and Complete.

      1. In Silverlight, click the Application Assignment page. Click the plus arrow next to a Layer and select the new version. Then complete the wizard.
  19. To update multiple images:
    1. In HTML5, in the Version Information tab for a Layer, select the version and click Update Assignments.

      1. In Silverlight, right-click the updated layer, and click Update Assignments.
      2. In the Select Version page, select the version you want to assign, and click the down arrow.
    2. In the Image Template Assignment tab, select the templates you want to update, and scroll down or click the down arrow.

    3. In the Elastic Assignment tab, if this App Layer is assigned to users, you can update them too. Click the down arrow.

    4. Click Confirm and Complete, or in the Confirm and Complete page, click Update Assignments.

  20. Once an image has a new version assigned, you must republish it.

Export Layers

App Layering 4.3 and newer let you export all layers and versions to the SMB File Share.

  1. Go to the Layers tab.
  2. Right-click on the background, and click Export.
  3. App Layering 4.4 and newer lets you specify a file share for the exported layers.
  4. ELM 4.5 and newer let you select the layers and versions that you want to export. Make your selections, and then click the down arrow.
  5. Review the list of layers/versions it will export, and click Export.
  6. If you look in your SMB share, in the \Unidesk\Exported Layers folder, you’ll see a folder for the OS Layer, and in there, you’ll see a folder for each Platform and Application Layer.
  7. After creating new layer versions, if you export layers again, it will only export the layers/versions that haven’t already been exported.
  8. If you right-click the background, and click Import…
  9. It only imports the layers/versions that are missing.

App Layering – OS Layer and Platform Layer

Last Modified: May 15, 2024 @ 8:50 am

244 Comments

Navigation

This page assumes the Enterprise Layer Manager (ELM) has already been imported and configured. This page is based on VMware vSphere. For Hyper-V and PvS focused instructions, see Create and update the OS Layer by CTP George Spiers. For Azure, see How to configure Citrix Cloud – App Layering 4.x to deliver virtualized apps and Office 365 caching – User Layers for XenApp and XenDesktop Service Cloud Workspaces in Microsoft Azure by CTP Christiaan Brinkhoff.

Change Log

Layers Overview

25-page Citrix App Layering Reference Architecture at Citrix Tech Zone details the following:

  • Why App Layering
  • Technical Overview of Citrix App Layering
  • Types of Layers
  • App Layering Integration with Citrix Provisioning and Citrix Machine Creation Services
  • Cross-Platform Support
  • App Layering Communication Flow
  • Availability, Backup, and Recovery – including User Layers

Enterprise Layer Manager (ELM) uses several types of layers:

  • Operating System Layer
  • Platform Layer
  • Application Layer
  • Image Template
  • User Layer

The master versions of all Layers are stored inside the Enterprise Layer Manager virtual appliance.

Citrix Blog Post How to approach designing your app layering strategy describes in which layer to install an application.

Citrix CTX225952 4.x Layering Best Practices

Layer Report – lists all of the Layers and the information associated with the layers. See Rob Zylowski at Citrix Blog Post Citrix App Layering and reporting.

Operating System Layer

Operating System Layer is just the base OS (with patches) and VMware Tools. Other components are usually installed in Platform and Application Layers.

  • If you install .NET Frameworks in the OS Layer, then you only need to run Windows Updates on the OS Layer. However, Office should always be installed in an Application Layer.
  • Windows Store apps should be removed from the OS Layer, not other layers.

Platform and Application Layers are tied to the OS Layer – The remaining layers (Platform and Application) are created from an OS Layer. These layers are linked to one OS Layer, and can’t be used on any other OS Layer.

  • If you upgrade the hypervisor tools in the OS Layer, then you might have to recreate the Platform Layer.

Only OS Layer captures changes to local groups and local apps – Any application that creates local users (e.g. XenApp 6.5) should be installed in the OS Layer. Platform Layer and Application Layers do not capture changes to local groups or local users.

Platform Layer

Platform Layer is the highest priority layer and should contain the following: (from CTX225997 Considerations When Creating a Platform Layer in Citrix App Layering 4.x)

  • Citrix Virtual Delivery Agent, or VMware Horizon Agent.
  • Citrix Provisioning Services Target Devices Software
  • NVIDIA Drivers
  • Join the Domain
  • Citrix Receiver – for the Single Sign-on Component
  • Citrix Workspace Environment Management Agent
  • Imprivata
  • Hypervisor Tools – if packaging or publishing to a different hypervisor than originally used to create the OS Layer.

SAM database changes (local users, local groups) are not captured in the Platform Layer. You might have to use group policy to create and populate local groups. For example, Citrix Virtual Delivery Agent creates local users adds domain users to local groups. See Direct Access Users Group Missing All Layers at Citrix Discussions.

  • Domain Join in Platform Layer does not capture adding Domain Admins to local Administrators group and Domain Users in the local Users group. Use Group Policy Restricted Groups or Group Policy Preferences Local Users and Groups to add these Domain Groups to the Local Groups.

  • Here are some additional settings in a Group Policy at Computer Configuration > Preferences folder > Control Panel Settings  Right-click the Local Users and Groups node, point to New, and select Local Group. More info at CTX259057 VDAs are not registering using a published image – Use GPO/GPP to add the proper accounts and services.
    • Action – Update – Group – Remote Desktop Users – Add Members “DOMAIN\Domain Users”
    • Action – Update – Group – Remote Desktop Users – Add Members “NT AUTHORITY\Authenticated Users”
    • Action – Update – Group – Performance Log Users – Add Members “NT Service\CitrixTelemetryService”
    • Action – Update – Group – Performance Monitor Users – Add Members “NT Service\BrokerAgent”
    • Action – Update – Group – Administrators – Add Members DOMAIN\Your_Citrix_Admins_Group
    • Action – Create – Group – Anonymous
    • Action – Create – Group – Direct Access Users – Add Members DOMAIN\Your_User_Group

Windows 10/11 apps should be removed from the OS Layer, not from the Platform Layer.

An Image Template (the composed machine that is published to the hypervisor) can contain only one Platform Layer. If you are creating a Platform Layer for Citrix Provisioning Services, then that one Platform Layer should include both the Citrix VDA and the Citrix PvS Target Device Software.

Application Layers

Application Layers contain anything not in the OS Layer or Platform Layer, including the following:

  • Applications
  • Antivirus
  • Print Drivers
  • SCCM Client

Per-user settings (profile changes) are not captured in an Application Layer.

When creating a Layered Machine, there are two methods of merging the Application Layers:

  • Pre-boot – ELM merges the App Layers with the OS Layer and Platform Layer to create a single monolithic disk file. This method provides the greatest application compatibility. Use this method for Apps with boot time services or drivers.
  • Elastic – When the user logs into a Layered Machine, a service looks in a file share for any Elastic Layers assigned to the user, and merges (mounts) them as the user logs in. Different users can have different Elastic Layers, even on multi-user Remote Desktop Session Host (XenApp) machines. However, Elastic Layering doesn’t work for apps that need boot-time services/drivers.

A single App Layer can be merged using either of these methods. If the App Layer doesn’t work Elastically, then you can mount it Pre-boot (Image Template) instead. There is no need to create separate App Layers for each mounting method.

Elastic App Layers are stored in a SMB file share. You can use any desired method to provide High Availability for this file share, including: Scale Out File Server, DFS Namespace/Replication, etc.

FSLogix creates local groups every time the service restarts, thus it works when installed inside an Application Layer.

Image Template

Image Template contains one OS Layer, one Platform Layer, and zero or more App Layers. The App Layers assigned in the Image Template are merged pre-boot.

You then Publish the Image Template to your hosting platform.

  • For MCS, the Template is pushed to a hypervisor (e.g. vSphere) virtual machine, which becomes the master image for an MCS Catalog.
  • For PvS, ELM creates a VHD file, and pushes it to a PvS vDisk Store, so you can assign it to Target Devices.

For Elastic Layers, you must enable Elastic Layers in the Image Template.

User Layers

User Layers allow users to install their own applications. In ELM 4.14 and newer, User Layers are fully supported.

User Layers require additional consideration for backup, replication, and recovery.

User Layers are tied to OS Layer – From Gunther Anderson: “Like App and Platform Layers, User Layer disks are tied to the OS layer they were originally built from. If you have a user login to images from two different OS layers, you will see the User Layer disks in two different directories on the share, one for each OS layer. The image itself knows what OS layer it was built from, and the ULayer service uses that information.”

  • If you want profile portability, store the profile outside of the User Layer by implementing Citrix Profile Management.

The default size for User Layers is 10 GB. You can change this size by setting HKLM\Software\Unidesk\Ulayer\DefaultUserLayerSizeInGb on the managed machines. Source = Understanding Elastic Layering > Scaling (tab) > User Layer Size.

Layering Tips

From Citrix Blog Post 5 Tips for Packaging Your Apps with Citrix App Layering:

  1. .NET Frameworks go in the OS Layer
    1. Store apps are removed from the OS Layer.
  2. Keep the layer as clean and as small as possible
    1. A packaging machine will not be part of your domain
    2. Delete any installers from the desktop, delete any temp directories, and empty the recycling bin
    3. If Windows Updates, delete the contents of C:\Windows\SoftwareDistribution\Download
  3. Underlying applications should be layered first, and then selected as prerequisite layers when you go to create a layer for the subsequent application
  4. Use  Application Layer Recipes
    1. Turn off the application’s auto-updater
    2. For antivirus, follow the manufacturer’s steps to “generalize” or remove any unique client identifiers
    3. Handle application licensing – rearm, activation, etc.
  5. Run ngen.exe update

Also see Citrix CTX225952 4.x Layering Best Practices:

  • Operating System Layer:
    • Application Layers are tied to the Operating System Layer.
    • ELM automatically upgrades OS Layer drivers. However, OS Layer Scripts should be updated reinstalling the Machine Tools.
    • .NET should be in the OS Layer.
    • OS Layer is lowest priority.
    • Patch OS by creating an OS Layer Version.
    • When patching, ensure Windows is activated.
    • VMware Tools goes in the OS Layer. Update it too.
    • Windows Store apps should be removed from the OS Layer.
  • Application Layers:
    • Per-user profile settings are not captured.
    • Local users and local groups are not captured. Use Group Policy Restricted Groups instead.
    • A single utility layer can include Java, Flash, Adobe Reader.
    • Turn off application automatic updates.
    • If domain membership required for an app installation, join domain, install app, remove from domain.
    • Antivirus can go in OS Layer or App Layer.
    • Printer drivers can be layered – but not elastically
    • Use Layer Recipes.
    • All Office apps needed by a machine/user should be combined into a single Office Layer
    • Office cannot be elastically layered
    • When patching Office, update the OS Layer first.
    • Max 50 layers per desktop.

CTX226984 App Layering/Unidesk: The list of Windows Updates is usually wrong in app/platform layers and published images/desktops.

Operating System Preparation

  1. See Citrix CTX225952 4.x Layering Best Practices
  2. Windows Server 2019 – Windows Server 2019 is supported in App Layering 1905 and newer
  3. Office 2019 – Office 2019 is supported in App Layering 1905 and newer
  4. Windows 11 is supported in App Layering version 2112 and later
  5. Windows 10
    1. Windows 11 22H2 and Windows 10 22H2 are supported in App Layering 2211 and newer.
    2. Windows 11 is supported in App Layering 2112 and newer.
    3. Windows 10 version 21H2 is supported in App Layering 2110 and newer.
    4. Windows 10 version 21H1 is supported in App Layering 2107 and newer.
    5. Windows 10 version 20H2 is supported in App Layering 2011 and newer.
    6. Windows 10 version 2004 is supported in App Layering 2008 and newer.
    7. Windows 10 version 1909 is supported in App Layering 2001 and newer.
  6. Create a virtual machine.
  7. If vSphere:
    1. Make sure your OS Layer creation machine has a NIC of type VMXNET 3.
    2. Paravirtual SCSI controllers are supported in App Layering 2001 and newer.
    3. On the VM Options tab, expand Boot Options, and make sure the Firmware is BIOS, not EFI.
  8. EFI:
    1. App Layering 2003 and newer has a ImportOsLayer.ps1 script that can import an EFI machine.
    2. Connectors with Compositing Engine enabled support EFI.
    3. Older versions of App Layering cannot import an EFI OS Layer.
    4. vSphere 6.7 defaults to EFI for new VMs.
  9. Install an operating system (Windows 11, Windows 10, or Windows 2022/2019/2016), and patch it.
  10. Install VMware Tools.
  11. DHCP – Make sure the NIC is set to DHCP.
  12. Workgroup – Don’t join the template machine to the domain. Leave it in a workgroup.
  13. RDSH – For RDSH machines, Citrix recommends installing RDSH in the OS Layer instead of the Platform Layer.
  14. Remote Desktop – Enable remote connections (Remote Desktop).

  15. Install Windows Updates.
  16. Disable Automatic Updates on the template machine. You can use layers to install updates. An easy method to disable it is in Group Policy (gpedit.msc) at Computer Configuration | Policies | Administrative Templates | Windows Components | Windows Update | Manage End User Experience | Configure Automatic Updates. Disable the setting.
  17. To stop Windows from performing maintenance and consuming 100% CPU, set the following registry value: (source = Win 10 Image – CPU Utilization 100% non-stop at Citrix Discussions):
    • HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\Schedule\Maintenance
      • MaintenanceDisabled (REG_DWORD) = 1
  18. If Citrix Provisioning, George Spiers says IPv6 should be disabled.
  19. Go to the downloaded App Layering 2403 files, right-click the citrix_app_layering_os_machine_tools_24.3.0.exe file, and click Run as administrator.
  20. Click Yes to extract the files.
  21. If you look on the taskbar, you might see an open program called Set KMS Version.
  22. Click Use KMS.
  23. Click Close when prompted a reboot is needed.
  24. Then close the window.
  25. If Set KMS Version did not run automatically, then manually run C:\Windows\Setup\scripts\SetKMSVersion.hta as administrator (elevated).
    1. Shift right-click the file to copy its full path.
    2. Open command prompt as administrator, paste the path, and run it from there.
    3. Click Use KMS.
    4. This adds the file runipkato.cmd to C:\Windows\Setup\scripts\kmsdir, which ELM will run when it publishes the image. The script installs the KMS Client key and activates it.
  26. If you have run KMS Setup multiple times (usually due to Machine Tools upgrades), check the registry for duplicates and remove the duplicates.
    1. In regedit, go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\Scripts\Startup\0\0. You should see kmssetup.cmd.
    2. If there are other registry keys named 1 or higher, check them for kmssetup.cmd. If true, then delete the duplicate keys so that only 0 remains.
    3. See CTX238316 After upgrading the OS Machine Tools, kmssetup.cmd runs twice at startup for more details.
  27. If this is a Windows 10 or Windows 11 virtual machine, and if you want to remove Store apps, remove them from the OS Layer instead of the Platform Layer.
    1. In App Layering 4.11 and newer, Store apps are supported, and it is no longer necessary to remove them.
    2. App Layering 4.7 and newer has a script at C:\Windows\Setup\Scripts\RemoveStoreApps.cmd that can remove the store apps. Note: this script removes Calculator, so you’ll probably want to find a replacement Calculator.
    3. Citrix Optimizer can remove Store apps.
    4. The Citrix Optimizer community marketplace at https://raw.githubusercontent.com/ryancbutler/Citrix_Optimizer_Community_Template_Marketplace/master/communitymarketplace.xml also has an App Layering Supplement.

  28. Run setup_x64.exe from C:\Windows\Setup\scripts. Make sure you run it elevated.
  29. In the Welcome to the InstallShield Wizard for the Citrix App Layering Image Preparation Utility 23.12.0.4 page, click Next.
  30. In the Specify your answer file page, click Next.
  31. In the InstallShield Wizard Completed page, click Finish.
  32. CTP George Spiers Citrix App Layering Preparation Script: runs a number of tasks to clean out temporary folders, clear out Event Log entries, remove ghost devices from Device Manager, etc.
  33. Run the ImportOsLayer.ps1 script to import your new OS Layer to ELM. Newer versions of ELM only support the ImportOsLayer.ps1 method of creating an OS Layer.

vSphere Connector

ELM uses Connectors to communicate to push images and layers to various hypervisors.

  1. In App Layering 2202 and newer, you can use the new HTML5 interface to create Connectors.

    1. In ELM 4.11 and newer, in the Internet Explorer Silverlight console, you can create or edit connectors at System > Connectors. This page also shows Connector Cache information. Caching improves performance of the connectors.
  2. See System requirements at Citrix Docs for the list of supported hypervisors and brokers.
  3. To create the vSphere connector, in the Choose a Connector Type window, select VMware vSphere.
  4. Click New.

  5. In App Layering older than version 2304, a new tab opens. Version 2304 and newer have a new interface for configuring the Connector.
  6. Give the Connector a name (e.g., vCenter name). The Connector specification includes specific storage, so the Connector name should indicate the storage name.

  7. Enter the vCenter FQDN and service account credentials.
    • The vCenter permissions needed by the service account are detailed at vSphere Permissions at Citrix Docs.
  8. Click Check Credentials.

  9. Scroll down and use the drop downs to select where you want Packaging VMs and Published Templates to be created.
    • The Packaging VMs and Published Templates will be created under the Virtual Machine Folder that you specify here.
  10. If MCS, in the Virtual Machine Template (optional) field, search for a Template VM that will be copied to create the MCS master image. The Template VM needs CPU, Memory, and GPU settings, but no disks. See Required information for this Connector Configuration at Citrix Machine Creation Services for vSphere Connector Configuration at Citrix Docs.
    • To ensure that the published images have the correct time zone, it may help to generate a new template for your Connector by having (or building) a Windows VM that has booted in the correct time zone. Shut it down, clone it, delete the attached disk from the clone, and convert that to a template for your Connector configuration in the Layering Management Console. More info at CTX230562 App Layering: Machine time on a published image is wrong at first boot.
  11. Packaging Cache Size in GB speeds up App Layer creation operations if you are creating multiple App Layers for the same OS/Platform combination. The size should be greater the size of the OS/Platform combinations.
  12. Offload Compositing – at the bottom of the connector, make sure Offload Compositing is enabled to speed up provisioning operations. In 2304 and newer, click Confirm and Complete.
  13. In older versions click Test.

    1. When the Test is successful, click Save.
    2. Then click Close.

Platform Layer

Create Packaging VM

  1. See Citrix CTX225952 4.x Layering Best Practices.
  2. See Citrix CTX225997 Considerations When Creating a Platform Layer in Citrix App Layering 4.x.
  3. Create your Hypervisor Connector before you create the Platform Layer. In the new HTML5 console in App Layering 2202 or newer, click Connectors on the left. Or in the Internet Explorer Silverlight console, go to System > Connectors to create a Connector.

  4. In the HTML5 console, click Layers on the left, switch to the Platform Layers tab on the right, and then click Create Platform Layer.

    1. In the older Internet Explorer Silverlight console, in the Layers tab, Platform Layers sub-tab, right-click in the grey area, and click Create Platform Layer.
  5. In the Layer Details page, give the Platform Layer a name and version. Note: Platform Layers are linked to OS Layers, so it’s best to indicate which OS Layer this Platform Layer is based on. You can’t use a Platform Layer created on one OS Layer on a different OS Layer.
  6. Enter a version number.
  7. Specify a Max Layer Size. Note: the packaging machine is thick provisioned using the size specified here, plus the size of the OS Layer.
  8. In the HTML5 interface, scroll down.

    1. In the Silverlight interface, click Next (down button).
  9. In the OS Layer page, select the OS Layer (and layer version) this Platform Layer will be based on.
  10. In the HTML5 interface, scroll down.

    1. In the Silverlight interface, click the next button (down arrow).
  11. In the HTML5 interface, change the selection to This platform layer will be used for publishing Layered Images.
    1. Use the drop downs to select the Hypervisor, Provisioning Service, and Connection Broker. These can be changed later.
    2. Select an existing vSphere connector.
    3. For Packaging Disk Filename, enter a name for the .vmdk disk that will be created in vSphere. Click Confirm and Complete.
    4. Then click Create Layer.
  12. In the Internet Explorer Silverlight interface, in the Connector page, if you already have a vSphere connector, select it, and click Next. If you don’t already have a vSphere connector, then click New to create one. Click the down arrow.

    1. In the Platform Types page, change the selection to This platform layer will be used for publishing Layered Images. The other selection is if you want to deploy the vSphere OS Layer on a different hypervisor (e.g. Azure).
    2. Use the drop downs to select the Hypervisor, Provisioning Method, and Connection Broker. These can be changed later. Click the down arrow.
    3. In the Packaging Disk page, enter a name for the .vmdk disk that will be created in vSphere. Click the down arrow.
    4. In the Icon Assignment page, select an icon, or upload a new one. Click the down arrow.
    5. In the Confirm and Complete page, click Create Layer.
  13. In the HTML5 interface, on the left is the Tasks node showing you the current progress. Click View Details.

    1. In the Silverlight interface, on the bottom of the screen, open the Tasks pane.
    2. Click the information icon to view what the task is doing.
  14. Eventually it will say Pending (Action Required), meaning it’s waiting for you to perform the packaging in vSphere.

Edit Packaging VM

  1. In vSphere Web Client, in the VMs and Templates view, expand the Layering folder, expand Packaging VMs, and click the new Packaging Machine.
  2. If you edit the VM’s hardware, and if Offload Compositing is enabled, then the Hard Disk is Thin Provisioned.

    1. If Offload Compositing is not enabled, then notice that the disk is Thick Provisioned.
  3. Open the VM’s console and login to the machine.
  4. Join it to the domain. Only join the Platform Layer to the domain. OS Layer and App Layers must not be joined to the domain. You’re welcome to change the computer name.

    • After joining the domain, move the computer object to your VDA OU so the GPO computer settings are applied to the Platform Layer.
  5. You can now install VDA software.
    • VDA 2112 is supported with App Layering 2112 and newer.
    • VDA 1912 LTSR is supported with App Layering 2001 and newer.
    • VDA 1909 is supported with App Layering 1910 and newer.
    • VDA 1906 is supported with App Layering 1907 and newer.
    • VDA 1903 is supported with App Layering 1905 and newer.

  6. Feel free to reboot the Packaging VM.
  7. Rob Zylowski at Imprivata App Layers at Citrix Discussions recommends installing Imprivata in the same Platform Layer that contains the VDA.
  8. According to Direct Access Users Group Missing All Layers at Citrix Discussions, the Platform Layer does not capture or merge changes to local groups.
    1. Use Group Policy Restricted Groups or Group Policy Preferences Local Users and Groups to configure local groups.
    2. At Computer Configuration >Preferences folder >Control Panel Settings, right-click the Local Users and Groups node, point to New, and select Local Group. More info at CTX259057 VDAs are not registering using a published image – Use GPO/GPP to add the proper accounts and services.
      • Action – Update – Group – Users – Add Members: “DOMAIN\Domain Users”
      • Action – Update – Group – Administrators – Add Members: “DOMAIN\Your_Citrix_Admins_Group”, “DOMAIN\Domain Admins”
      • Action – Update – Group – Remote Desktop Users – Add Members: “NT AUTHORITY\Authenticated Users”
      • Action – Update – Group – Performance Log Users – Add Members: “NT Service\CitrixTelemetryService”
      • Action – Update – Group – Performance Monitor Users – Add Members: “NT Service\BrokerAgent”
      • Action – Create – Group – Anonymous
      • Action – Create – Group – Direct Access Users – Add Members: “DOMAIN\Your_RDP_Allowed_User_Group”
  9. If Citrix Provisioning:
    1. Install the Citrix Provisioning Target Device Software in the Platform Layer. The ELM Templates only allow one Platform Layer per template, so you’d need to install both VDA and Provisioning Services Target Device components in a single Platform Layer.
    2. Rearm KMS licensing (slmgr /rearm). MCS does this automatically during Image Prep.
  10. From Citrix CTX225997 Considerations When Creating a Platform Layer in Citrix App Layering 4.x): Additional software to install in the Platform Layer:
    • NVIDIA Drivers
    • Join the Domain – after joining, login as network account, then login as local account, and delete the profile of the network account.
    • Citrix Workspace App – for the Single Sign-on Component
    • Citrix Workspace Environment Management Agent
    • Hypervisor Tools – if packaging or publishing to a different hypervisor than the one originally used to create the OS Layer.
  11. Windows 10/11 apps should be removed from the OS Layer, not from the Platform Layer.
  12. CTX226984 App Layering/Unidesk: The list of Windows Updates is usually wrong in app/platform layers and published images/desktops.
  13. When done installing components, finalize the layer:
    1. CTP George Spiers Citrix App Layering Preparation Script: runs a number of tasks to clean out temporary folders, clear out Event Log entries, remove ghost devices from Device Manager, etc.
    2. Double-click the Shutdown for Finalize icon on the desktop. If it finds issues, it will tell you what to do (e.g. reboot needed).
    3. If it tells you that you need to run ngen, then run the following commands:

      "c:\windows\Microsoft.NET\Framework64\v4.0.30319\ngen.exe" update
"c:\windows\Microsoft.NET\Framework\v4.0.30319\ngen.exe" update
    4. Otherwise, it will shut down the VM.
  14. If Offload Compositing is enabled in your Connector, then the Packaging VM will reboot into Windows PE and automatically run the CompositingEngine.
  15. ELM will automatically transfer the files from the Compositing Engine. You don’t have to click Finalize.

  16. If Compositing Engine is not enabled in your Connector:
    1. Back in the ELM Internet Explorer Silverlight Console, in Layers > Platform Layers, right-click the Editing layer, and click Finalize.
    2. In the Confirm and Complete page, click Finalize.
    3. You can click the information icon next to the running task to see what it’s doing.

  17. Eventually the icon will say Deployable.

  18. In the HTML5 interface, the tabs show you details on the layer.

    1. In the Internet Explorer Silverlight interface, you can click the information icon on the Platform Layer to view its details.

Next Steps

Update OS or Platform Layers

  1. In the HTML5 Interface, select a layer, switch to the Version Information tab, and click Add Version.

    1. In the Silverlight interface, right-click an OS Layer or a Platform Layer, and click Add Version.
  2. In the Version Details page, select a Base Version that you want to update. In the New Version field, enter a new version. In HTML5 Interface, scroll down. In Silverlight interface, click Next.

  3. In the OS Layer page, select an OS Layer version, and scroll down or click Next.

  4. In the HTML5 Interface, in the Platform Types section, most of this should already be filled in. Choose your Connector Configuration and then click Confirm and Complete.
  5. In the Internet Explorer Silverlight interface, in the Connector page, select a Connector, and click Next.

    1. In the Platform Types page, click Next.
    2. In the Packaging Disk page, click Next.
    3. In the Confirm and Complete page, click Add Version.
  6. The Tasks page and Task Details shows the current progress and will eventually say Action Required.


  7. When the Packaging Machine is deployed, you can connect to its console and perform any desired updates.

  8. When done installing updates, finalize the layer:
    1. George Spiers Citrix App Layering Preparation Script: runs a number of tasks to clean out temporary folders, clear out Event Log entries, remove ghost devices from Device Manager, etc.
    2. Double-click the Shutdown for Finalize icon on the desktop. If it finds issues, it will tell you what to do (e.g. reboot needed). Otherwise, it will shut down the VM.
  9. If Offload Compositing engine is not enabled in your Connector:
    1. When done updating the Packaging Machine, right-click the Layer that is marked as Editing, and click Finalize.
    2. In the Confirm and Complete page, click Finalize.
  10. View the task details to see the current progress.

  11. To confirm that you have a new version, the layer’s Version Information tab shows the new version. Or in the Silverlight interface move your mouse over the layer icon, and click the information icon. The available versions are shown.


  12. There are two methods of assigning a new version: one image at a time, or multiple images.
  13. To edit one image:
    1. Go to the Images tab.
    2. Select an Image, and click Edit Template.
    3. Scroll down or click the OS Layer or Platform Layer page.
    4. Click the plus arrow next to a Layer and select the new version. Then complete the wizard.

  14. To update multiple images:
    1. In HTML5, select the Layer, switch to the Version Information tab, select a version, and click Update Assignments.

      1. In Silverlight, on the Layers tab, right-click the updated layer, and click Update Assignments.
      2. In the Select Version page, select the version you want to assign, and click Next.
    2. In the Image Template Assignment page, select the templates you want to update, and scroll down or click Next.

    3. Click Confirm and Complete, or in the Confirm and Complete page, click Update Assignments.

  15. Once an image has a new version assigned, go to the Images tab, and republish the image.

App Layering – Enterprise Layer Manager (ELM) 2409

Last Modified: Nov 7, 2024 @ 3:22 am

128 Comments

Navigation

These App Layering pages focus on VMware vSphere as the hypervisor.

Change Log

Licensing

From Citrix Blog Post A Breakdown of Citrix App Layering Features by Edition: Citrix App Layering is available in all Citrix Virtual Apps and Desktops (CVAD) editions and all Citrix DaaS (Citrix Cloud) editions. This means that you can do the following across any number of Citrix Virtual Apps and Desktops (CVAD) sites in your environment:

  • Create an unlimited number of OS, platform and application layers
  • Create an unlimited number of layered images
  • Create an unlimited number of elastic layers

Citrix Virtual Apps and Desktops (CVAD) Premium Edition customers and all Citrix DaaS customers (Citrix Cloud) also benefit from:

  • Multiple hypervisors and/or cloud connections (e.g., Citrix Hypervisor and Azure or Citrix Hypervisor and Hyper-V).
    • Non-Premium sites are limited to one hypervisor or cloud connection type.
  • Multiple provisioning mechanisms (e.g. Machine Creation Services and Citrix Provisioning).
    • Non-Premium sites must select MCS or CPV and use it exclusively with Citrix App Layering.
  • Multiple broker types/platforms (e.g. Citrix Virtual Apps and Desktops (CVAD) with VMware Horizon View).
    • Non-Premium sites can only use App Layering within their Citrix Virtual Apps and Desktops (CVAD) sites
  • User Layers

For Citrix Cloud – Those customers using the Citrix Virtual Apps and Desktops (CVAD) Service are entitled to Premium-level features including all Citrix App Layering capabilities.

Upgrade Enterprise Layer Manager

If you are deploying a new ELM appliance, skip to Import Enterprise Layer Manager.

If you are upgrading from 2403 or older, first upgrade the existing appliance to version 2403.9. Then deploy a new 2409 appliance. Then run the migration wizard from the 2403.9 appliance.

To upgrade the older appliance:

  1. When you login to the ELM, if you click your user menu on the top right, then you might see Upgrade Appliance with an alert next to it. If you don’t see it yet, then you might have to wait for the Download task to complete.

  2. If you don’t see the upgrade notification, then download it manually:
    1. Download version 2403.9 upgrade package from Citrix App Layering 2403 at Citrix Downloads. Look for the section named For an existing deployment, download the upgrade package.
    2. In the App Layering file share, create an Upgrade folder.
    3. Unzip the Upgrade Package and copy the citrix_app_layering_upgrade_pkg_24.3.9.vhd file to the Upgrade folder in the App Layering file share.
    4. Click your name on the top right and then click Upgrade Appliance.
    5. If the field is not already populated, then click Browse.
    6. Browse the file share, select the upgrade disk, and then click Save.

  3. Click Confirm and Complete.
  4. In the Confirm Upgrade page, click Upgrade.

  5. Wait for the upgrade to complete.
  6. Then click Return to login and login.
  7. Click Dismiss acknowledging that connector caches have some items removed.
  8. On the top right, click your username and then click About to see the current version, which should be 24.3.9.

  9. Import a new ELM with version 2409 or newer.
  10. In the older 2403.9 appliance, click your name on the top right and then click Migrate Appliance.
  11. Enter the address for the new 2409 or newer appliance.
  12. Change Migration Reason to Move.
  13. Click Confirm and Complete.
  14. Click Confirm. Click Migrate.

  15. In the Tasks page, click View Details for the Active task to see the progress.

Upgrade OS Layer

  1. From Gunther Anderson at Citrix: You do not uninstall or upgrade the Citrix App Layering Image Preparation Utility – Setup_x64.exe. The current drivers are installed in the ELM, and every time the ELM produces an image for any purpose, it injects the current drivers into it. You do not need to touch your OS layer for that. But you should re-publish all images.
  2. In a new OS Layer version, you should download and run citrix_app_layering_os_machine_tools_24.9.0.exe to allow it to upgrade your system scripts, but you don’t need to do anything beyond that. For Office 2019, your Machine Tools scripts must be version 1905 or later.
  3. When Yes when prompted that the tools will be extracted into C:\Windows\Setup\Scripts.
  4. Replace the existing files. This is especially important for fixing Office activation issues.
  5. If you look on the taskbar, you might see an open program called Set KMS Version.
  6. Click Use KMS.
  7. Then close the window.
  8. To fix Office activation issues, you’ll also need to create a new version of your Office layer, rerun the optimization tool, and then publish the updated image. More details at Office MAK licensing issues at Citrix Discussions.
  9. Re-publish your images so ELM can inject the new drivers.

Upgrade Provisioning Services Agent

  1. If you recently upgraded Provisioning Services server, then you might have to re-register the PVS snap-in: 
    "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe" "c:\program files\citrix\provisioning services console\Citrix.PVS.snapin.dll"
  2. Go to the Citrix App Layering 2409 files and run citrix_app_layering_agent_installer.exe.
  3. Click Yes to upgrade the agent.
  4. In the Welcome to the InstallShield Wizard for Citrix App Layering Agent page, click Next.
  5. In the InstallShield Wizard Completed page, click Finish.

Import Enterprise Layer Manager Appliance

This section is for new installs.

Reference Architecture: App Layering:

  • Layered images, Elastic Layers, and User Layers do not communicate with ELM, so ELM’s availability is not a concern.
    • Do not change the vCPUs or memory allocated to the ELM appliance.
  • All created layers are stored on the ELM appliance. Simply backup the appliance.
    • Layers can be exported from the ELM appliance to a file share and optionally imported to another ELM appliance.
  • Elastic Layers and User Layers are always-open VHD files stored on a file share(s) that is separate from the ELM.
    • The file share(s) should be highly available. Use a clustering technology (e.g. Scale Out File Server) that supports always-open VHD files.
    • It’s not necessary to backup Elastic Layers, but you might want to replicate them to a different datacenter for multi-datacenter access. Make sure the replication tool supports always-open VHD files.
    • User Layers should be backed up and/or replicated. Use a backup method that supports always-open VHD files.

Download Appliance

  1. You can download App Layering 2409 Appliance Installation Package from Citrix Downloads.
  2. After downloading, extract the 2409.zip file.

Import ELM Appliance

To import the ELM appliance:

  1. In vSphere Web Client, right-click a cluster, and click Deploy OVF Template.
  2. In the Select an OVF template page, browse to the vmware_24.9.0.1.ova file, and click Next.
  3. In the Select name and location page, give the machine a name, and click Next.
  4. In the Select a compute resource page, select a cluster, and click Next.
  5. In the Review details page, click Next.
  6. In the Accept license agreements page, click Accept, and then click Next.
  7. In the Select storage page, select a datastore. The ELM appliance stores all master layers inside the appliance, so ensure there’s sufficient disk space (typically 300-500 GB) for the virtual appliance.
    1. You can view the appliance’s consumed disk space inside the ELM Management Console at System > Monitoring and Storage, or System > Manage Appliance.
    2. To expand the storage, either increase the existing disk size, or add a disk to the VM. Then, on the right, is a link to Expand Storage.

  8. Select a datastore, select thin provision, or not, then click Next.
  9. In the Select networks page, click Next.
  10. In the Customize template page, click Next.
  11. In the Ready to complete page, click Finish.
  12. See Firewall ports at Citrix Docs.

Configure ELM IP Address

  1. Once imported, power on the ELM appliance.
  2. Open the virtual machine console.
  3. After the RUN_ONCE commands are complete, press enter to show the login prompt, and then login to the console as administrator with a password of Unidesk1.
  4. Enter c to configure networking.
  5. Enter s to assign a static network.
  6. Enter a new IP address for this appliance. Then enter y to save settings and restart networking.
  7. Press <Enter> to continue.
  8. While here, feel free to configure the time zone.
  9. Press / to search. For Central Time, search for chicago, and note the time zone number.
  10. Press Q to quit the display.
  11. Enter the time zone number to configure it.
  12. NTP is configured to use Internet servers. Feel free to change them.

First Login

  1. In App Layering 2206 and newer, use Edge or Chrome to connect to the ELM. Login using administrator and Unidesk1.
  2. The first time you logon, you are prompted to accept the End User License Agreement.
  3. Then you are prompted to set three passwords.

    You then see the Get Started wizard.

Appliance Certificate

  1. In the HTML5 console, go to System > HTTP Certificate Settings.
  2. In HTML5 console, on the right, click Upload to replace the default management certificate.
  3. Browse to a PEM file that contains an unencrypted RSA key, and one certificate (no chain). You can use OpenSSL to convert a .pfx file to a PEM file.
  4. Make sure it says that the web server will restart, which means that it’s a valid certificate.
  5. It might take a few minutes to apply. Eventually, you should be able to point your browser to the https URL and not see any certificate errors.
  6. In HTML5 console, at System > Security and Retention Settings, you can change the management console timeout.

File Share

  1. On a Windows file server, create a new share that will store the Elastic Layers. Only SMB shares are supported with Elastic Layers. NFS shares will not work with Elastic Layers.
  2. For High Availability, you can use any file server High Availability technology like File Server Scale-out Clustering, DFS, etc. For local high availability, Citrix recommends clustering over DFS Replication since DFS failure requires reboot of Elastic Layered Machines.
    1. Elastic Layers are always-open VHDX files that can’t be replicated using DFS. For HA, build a File Server cluster, like Microsoft Scale Out File Server.,that supports SMB3 Continuous Availability.
  3. For DR Elastic Layer machines, the registry value HKEY_LOCAL_MACHINE\SOFTWARE\Unidesk\ULayer:RepositoryPath can be configured to point to a file share in a DR site. See CTX222107 You can change the Elastic Layer repository in the registry without reimaging (4.x).
  4. Give Everyone (or equivalent) Full Control to the share.
  5. On the Security tab, make sure the Users groups only have Read access (no Modify/Write).
  6. Add a service account to the share and give it Modify access. ELM uses this service account to upload elastic layers to the share.
  7. In App Layering 2206 and newer, in Chrome or Edge, go to System and then Network File Share.

    1. On the top right, click Edit.
    2. Enter the path and service account credentials. Click Confirm and Complete.
    3. Click Save.

In App Layering newer than 2204, you can use Chrome/Edge.

  1. Go to System > Directory Services.
  2. Click Add Directory Junction.
  3. Enter the address of a domain controller or LDAP Load balancing VIP. According to CTP George Spiers at Citrix Discussions, instead of entering a single domain controller address, you can enter your domain’s FQDN (domain.local) and it will use DNS to find a domain controller.
  4. . Enter bind account credentials. Click Connect.
  5. Click Accept and Continue.
  6. For Specify start point, click the field and select the Base Distinguished Name.
  7. Give the directory junction a friendly name. Then click Confirm and Complete.

Role Based Access

This is configurable in the HTML5 interface in Citrix App Layering 2204 and newer.

  1. On the left, click System. In the middle, click Administrators. On the right, on the Directory Administrators tab, click Add Administrators.
  2. Click Add Accounts.
  3. Search for the new admin group, check the box next to it, and click Save.
  4. Click Confirm and Complete.
  5. Click Add User.
  6. App Layering 2306 grant the Reader role by default. You can change the role by editing the user.
  7. Click the drop-down to see other available roles.
  8. When done, click Confirm and Complete.

User Layers Storage Locations

ELM 4.14 and newer support User Layers.

File shares for User Layers are configured at System > User Layer Storage Locations. Each Storage Location can be assigned to different user groups. And you can prioritize the Storage Locations. See Add storage locations for User layers at Citrix Docs. And see David Wilkinson Citrix Application Layering – User layers.

For each new Storage Location:

  1. Create a Users folder in the root of each share.
  2. Each Users folder needs permissions that look like the following. CREATOR OWNER needs Full Control. The Users group needs Create Folder/Append Data permission to This folder only.
  3. In ELM, add Storage Locations and assign them to groups. The first one you add is the default Storage Location for users not assigned to any other Storage Location.
  4. Then you can add more Storage Locations for specific user groups.


  5. If users are assigned to multiple Storage Locations, click Prioritize Storage Locations to prioritize the assignment.

Citrix Provisioning Publishing Agent

To publish to Citrix Provisioning, you install the App Layering Agent on the Citrix Provisioning Servers. It’s only needed on one Provisioning Server.

The installation of the Agent can be automated. See Dennis Span Citrix App Layering Agent unattended installation.

From Install the App Layering Agent (required for PVS and Connector Scripts) at Citrix Docs.

  1. Ensure the Citrix Provisioning services are running as a domain account. Network Service won’t work.
  2. Run the following command on the PvS 7.7 or newer Server. Note, if you upgrade PvS, you’ll have to run this command again. 
    "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe" "c:\program files\citrix\provisioning services console\Citrix.PVS.snapin.dll"

    1. If Citrix Provisioning 7.6 or newer, then run the following command instead: 
      "C:\Windows\Microsoft.NET\Framework64\v4.0.30319\InstallUtil.exe" "c:\program files\citrix\provisioning services console\MCliPSSnapIn.dll"
  3. Go to the App Layering 2409 files you downloaded from Citrix Downloads and run citrix_app_layering_agent_installer.exe.
  4. In the Welcome to the InstallShield Wizard for Citrix App Layering Agent page, click Next.
  5. In the License Agreement page, select I accept the terms in the license agreement, and click Next.
  6. In the Agent Port page, click Next.
  7. In the Ready to Install the Program page, click Install.
  8. Enter the ELM FQDN, enter ELM credentials, and click Register.
  9. Registration logs can be found at C:\Program Files (x86)\Citrix\Agent\Logs.
  10. In the InstallShield Wizard Completed page, click Finish.
  11. When an image is published to Provisioning Services, ELM can run a script. Citrix has a sample Versioning and Convert VHD to VHDX script that converts the VHD file to VHDX, and/or adds the published image as a version. The script files can be installed on the PvS server at this time. Later, you specify the path to the script when you create the PvS Connector in ELM while creating an image template.
  12. Citrix also has a BootPrivate script that modifies the vDisk mode to Private, boots the vDisk on a pre-defined target so that it can run pre-defined layer scripts, shuts down the target, waits for that shutdown, and then switches the mode back to standard.

Next Steps