Citrix Virtual Apps and Desktops service

Microsoft Azure Resource Manager virtualization environments

Follow the guidance in this article when using the Microsoft Azure Resource Manager to provision virtual machines in your Citrix Virtual Apps or Citrix Virtual Desktops service deployment.

We assume you are familiar with the following:

Note:

Azure supports disk encryption at rest by default, using Azure-managed encryption keys. This form of encryption is used by all catalogs in MCS and requires no user configuration.

Azure on-demand provisioning

When you use MCS to create machine catalogs in the Azure Resource Manager, the Azure on-demand provisioning feature:

  • Reduces your storage costs
  • Provides faster catalog creation
  • Provides faster virtual machine (VM) power operations

For administrators, on-demand provisioning introduces no differences in the Studio procedures for creating host connections and MCS machine catalogs. The differences lie in how and when resources are created and managed in Azure, and VM visibility in the Azure portal.

Note:

Use the full Studio version to add Azure host connections. The Web version of Studio does not allow you to add Azure host connections.

Before Citrix Virtual Apps and Desktops service integrated Azure on-demand provisioning, MCS behavior was different. When MCS created a catalog, VMs were created in Azure during the provisioning process.

With Azure on-demand provisioning, VMs are created only when Citrix Virtual Apps and Desktops initiates a power-on action, after the provisioning completes. A VM is visible in the Azure portal only when it is running. In Studio, VMs are visible, if they’re running.

When you create an MCS catalog, the Azure portal displays the resource groups, network security group, storage accounts, network interfaces, base images, and identity disks. The Azure portal does not show a VM until Citrix Virtual Apps and Desktops initiates a power-on action for it. Then, the VM’s status in Studio changes to On.

  • For a pooled machine, the operating system disk and write-back cache exist only when the VM exists. The cache can result in significant storage savings if you routinely shut down machines (for example, outside of working hours).
  • For a dedicated machine, the operating system disk is created the first time the VM is powered on. It remains in storage until the machine identity is deleted.

When Citrix Virtual Apps and Desktops initiates a power-off action for a VM, that machine identity is deleted in Azure. It no longer appears in the Azure portal. (In Studio, the VM’s status changes to Off.)

Catalogs created before on-demand provisioning Machine catalogs created before Citrix Virtual Apps and Desktops service supported the Azure on-demand provisioning feature (mid-2017) behaved differently. VMs in those catalogs are visible in the Azure portal if they’re running. You cannot convert an image in a region other than where MCS provisions the catalog. The image is copied to a VHD in a conventional storage account in the catalog’s region. It is then converted back to a managed disk.

On the Storage and License Types page of the catalog creation wizard, you can select a check box to use conventional storage accounts instead of managed disks. This check box is disabled when you are provisioning in an Azure region that does not support managed disks.

Create a connection to Azure Resource Manager

Create and manage connections describes the wizards that create a connection. The following information covers details specific to Azure Resource Manager connections.

Considerations:

  • Service principals must have been granted contributor role for the subscription.
  • When creating the first connection, Azure prompts you to grant it the necessary permissions. For future connections you must still authenticate, but Azure remembers your previous consent and does not display the prompt again.
  • Accounts used for authentication must be a co-administrator of the subscription.
  • The account used for authentication must be a member of the subscription’s directory. There are two types of accounts to be aware of: ‘Work or School’ and ‘personal Microsoft account.’ See CTX219211 for details.
  • While you can use an existing Microsoft account by adding it as a member of the subscription’s directory, there can be complications if the user was previously granted guest access to one of the directory’s resources. In this case, they might have a placeholder entry in the directory that does not grant them the necessary permissions, and an error is returned.

    Rectify this by removing the resources from the directory and add them back explicitly. However, exercise this option carefully, because it has unintended effects for other resources that account can access.

  • There is a known issue where certain accounts are detected as directory guests when they are actually members. Configurations like this typically occurs with older established directory accounts. Workaround: add an account to the directory, which takes the proper membership value.
  • Resource groups are simply containers for resources, and they can contain resources from regions other than their own region. This can potentially be confusing if you expect resources displayed in a resource group’s region to be available.
  • Ensure your network and subnet are large enough to host the number of machines you require. This requires some foresight, but Microsoft helps you specify the right values, with guidance about the address space capacity.

There are two ways to establish a host connection to Azure Resource Manager:

  • Authenticate to Azure Resource Manager to create a service principal.
  • Use the details from a previously created service principal to connect to Azure Resource Manager.

Authenticate to Azure Resource Manager to create a service principal

Before you start, ensure:

  • You have a user account in your subscription’s Azure Active Directory tenant.
  • The Azure AD user account is also a co-administrator for the Azure subscription you want to use for provisioning resources.

In the Add Connection and Resources wizard:

  1. On the Connection page, select the Microsoft Azure connection type and your Azure environment.
  2. On the Connection Details page, enter your Azure subscription ID and a name for the connection. The connection name can contain 1–64 characters, and cannot contain only blank spaces or the characters \/;:#.*?=<>|[]{}"'()'). After you enter the subscription ID and connection name, the Create new button is enabled.
  3. Enter the Azure Active Directory account user name and password.
  4. Click Sign in.
  5. Click Accept to give Citrix Virtual Apps and Desktops the listed permissions. Citrix Virtual Apps and Desktops creates a service principal that allows it to manage Azure Resource Manager resources on behalf of the specified user.
  6. After you click Accept, you are returned to the Connection page in Studio. Notice that when you successfully authenticate to Azure, the Create new, and Use existing buttons are replaced with Connected, and a green check mark indicates the successful connection to your Azure subscription.
  7. Indicate which tools to use to create the virtual machines, and then click Next. (You cannot progress beyond this page in the wizard until you successfully authenticate with Azure and accept giving the required permissions.
  8. Resources comprise the region and the network.

    • On the Region page, select a region.
    • On the Network page,
    • Type a 1–64 character resources name to help identify the region and network combination in Studio. A resource name cannot contain only blank spaces, and cannot contain the characters \/;:#.*?=<>|[]{}"'()'.
    • Select a virtual network and resource group pair. (Since you can have more than one virtual network with the same name, pairing the network name with the resource group provides unique combinations.) If you selected a region on the previous page that does not have any virtual networks, you must return to that page and select a region that has virtual networks.
  9. Complete the wizard.

Use the details from a previously created service principal to connect to Azure Resource Manager

To create a service principal manually, connect to your Azure Resource Manager subscription and use the PowerShell cmdlets provided in the following sections.

Prerequisites:

  • $SubscriptionId: Azure Resource Manager SubscriptionID for the subscription where you want to provision VDAs.
  • $AADUser: Azure AD user account for your subscription’s AD tenant. Make the $AADUser the co-administrator for your subscription.
  • $ApplicationName: Name for the application to be created in Azure AD.
  • $ApplicationPassword: Password for the application. You use this password as the application secret when creating the host connection.

To create a service principal:

  1. Connect to your Azure Resource Manager subscription.

    Login-AzureRmAccount

  2. Select the Azure Resource Manager subscription where you want to create the service principal.

    Select-AzureRmSubscription -SubscriptionID $SubscriptionId;

  3. Create the application in your AD tenant.

    $AzureADApplication = New-AzureRmADApplication -DisplayName $ApplicationName -HomePage "https://localhost/$ApplicationName" -IdentifierUris https://$ApplicationName -Password $ApplicationPassword

  4. Create a service principal.

    New-AzureRmADServicePrincipal -ApplicationId $AzureADApplication.ApplicationId

  5. Assign a role to the service principal.

    New-AzureRmRoleAssignment -RoleDefinitionName Contributor -ServicePrincipalName $AzureADApplication.ApplicationId –scope /subscriptions/$SubscriptionId

  6. From the output window of the PowerShell console, note the ApplicationId. You provide that ID when creating the host connection.

In the Add Connection and Resources wizard:

  1. On the Connection page, select the Microsoft Azure connection type and your Azure environment.
  2. On the Connection Details page, enter your Azure subscription ID and a name for the connection. (The connection name can contain 1–64 characters, and cannot contain only blank spaces, or non-ASCII or special characters.
  3. Click Use existing. Provide the subscription ID, subscription name, authentication URL, management URL, storage suffix, Active Directory ID or tenant ID, application ID, and application secret for the existing service principal. After you enter the details, the OK button is enabled. Click OK.
  4. Indicate which tools to use to create the virtual machines, and then click Next. The service principal details you provided are used to connect to your Azure subscription. (You cannot progress beyond this page in the wizard until you provide valid details for the Use existing option.)
  5. Resources comprise the region and the network.

    • On the Region page, select a region.
    • On the Network page, type a 1–64 character resources name to help identify the region and network combination in Studio. A resource name cannot contain only blank spaces, or non-ASCII or special characters.
    • Select a virtual network and resource group pair. (Since you can have more than one virtual network with the same name, pairing the network name with the resource group provides unique combinations.) If you selected a region on the previous page that does not have any virtual networks, you must return to that page and select a region that has virtual networks.
  6. Complete the wizard.

Create a machine catalog using an Azure Resource Manager master image

This information is a supplement to the guidance in Create Machine Catalogs.

A master image is the template that is used to create the VMs in a machine catalog. Before creating the machine catalog, create a master image in Azure Resource Manager. For general information about master images, see Create machine catalogs.

In the machine catalog creation wizard:

  • The Operating System and Machine Management pages do not contain Azure-specific information. Follow the guidance in the Create machine catalogs article.

  • On the Master Image page, select a resource group and then navigate (drill down) through the containers to the Azure VHD you want to use as the master image. The VHD must have a Citrix VDA installed on it. If the VHD is attached to a VM, the VM must be stopped.

  • The Storage and License Types page appears only when using an Azure Resource Manager master image.

    Storage and License Types page

    You have the following storage types to use for the machine catalog:

    • Premium SSD. Delivers high-performance and low-latency disk support for VMs with I/O-intensive workloads.
    • Standard SSD. Offers a cost-effective storage option optimized for workloads that need consistent performance at lower IOPS levels.
    • Standard HDD. Delivers reliable, low-cost disk support for VMs running latency-insensitive workloads.

    Important:

    • The Standard HDD and Premium SSD storage types apply only to unmanaged disks.
    • The Standard SSD storage type is available only in the web-based console and applies only to Azure Managed Disks.

    The storage type determines which machine sizes are offered on the Virtual Machines page of the wizard. Both storage types make multiple, synchronous copies of your data within a single data center. For details about Azure storage types and storage replication, see the following:

    Select whether to use existing Windows licenses. Using Windows licenses along with Windows images (Azure platform support images or custom images) lets you run Windows VMs in Azure at a reduced cost. There are two types of licenses:

    • Windows Server license. Lets you use your Windows Server or Azure Windows Server licenses, allowing you to utilize Azure Hybrid Use Benefits (HUB). For details, see https://azure.microsoft.com/pricing/hybrid-use-benefit/. HUB reduces the cost of running VMs in Azure to the base compute rate, waiving the cost of extra Windows Server licenses from the Azure gallery.

    • Windows Client license. Lets you bring your Windows 10 licenses to Azure, allowing you to run Windows 10 VMs in Azure without the need for extra licenses. For details, see Client Access Licenses and Management Licenses.

    Note:

    The Windows Client license option varies depending on the operating system you select during machine catalog setup. If you select Multi-session OS, the option appears as Use my Windows 10 licenses. If you select Single-session OS, the option appears as Use my Windows Client licenses.

    You can verify that the provisioned VM is utilizing the licensing benefit by running the following PowerShell command: Get-AzM -ResourceGroup MyResourceGroup -Name MyVM.

    Alternatively, you can use the Get-Provscheme PowerShell SDK to perform the verification. For example: Get-Provscheme -ProvisioningSchemeName "My Azure Catalog". For more information about this cmdlet, see https://developer-docs.citrix.com/projects/citrix-virtual-apps-desktops-sdk/en/latest/MachineCreation/Get-ProvScheme/.

    Azure Managed Disks are used for VMs in the catalog by default. If you want to use regular storage accounts instead, select the check box at the bottom of the page. The Use unmanaged disks instead of Azure Managed Disks for VMs in this catalog check box is available only in the legacy console.

    Azure Shared Image Gallery (SIG) is a repository for managing and sharing images. It lets you make your images available throughout your organization. We recommend that you store a master image in SIG when creating large non-persistent machine catalogs because doing that enables faster reset of VDA OS disks. The Place image in Azure Shared Image Gallery check box is available only in the web-based console.

  • On the Virtual Machines page, indicate how many VMs you want to create. You must specify at least one. Select a machine size. After you create a catalog, you cannot change the machine size. If you later want a different size, delete the catalog and then create a catalog that uses the same master image and specifies the desired machine size.

    If you select the Place image in Azure Shared Image Gallery check box on the Storage and License Types page, the Azure Shared Image Galley settings section appears, letting you specify more SIG settings:

    • Ratio of virtual machines to image replicas. Lets you specify the ratio of virtual machines to image replicas that you want Azure to keep. By default, Azure keeps a single image replica for every 40 non-persistent machines. For persistent machines, that number defaults to 1,000.

    • Maximum replica count. Lets you specify the maximum number of image replicas that you want Azure to keep. The default is 10.

Virtual machine names cannot contain non-ASCII or special characters.

  • (When using MCS) On the Resource Groups page, choose whether to create resource groups or use existing groups.
    • If you choose to create resource groups, click Next.
    • If you choose to use existing resource groups, select groups from the Available Provisioning Resource Groups list. Remember: Select enough groups to accommodate the machines you’re creating in the catalog. Studio displays a message if you choose too few. You might want to select more than the minimum required if you plan to add more VMs to the catalog later. You can’t add more resource groups to a catalog after the catalog is created.

    For more information, see Azure resource groups.

  • The Network Cards, Computer Accounts, and Summary pages do not contain Azure-specific information. Follow the guidance in the Create Machine Catalogs article.

Complete the wizard.

Azure throttling

Azure Resource Manager throttles requests for subscriptions and tenants, routing traffic based on defined limits, tailored to the specific needs of the provider. See Throttling Resource Manager requests on the Microsoft site for more information. Limits exist for subscriptions and tenants, where managing many machines can become problematic. For example, a subscription containing many machines might experience performance problems related to power operations.

To help mitigate these issues, Citrix Virtual Apps and Desktops service allows you to remove MCS internal throttling to use more of the available request quota from Azure.

Citrix recommends the following optimal settings when powering VMS on/off in large subscriptions, for example, those containing 1000 VMs:

  • Absolute simultaneous operations - 500
  • Maximum new operations per minute - 2000
  • Max concurrency of operations - 500

Use Studio to configure Azure operations for a given host connection:

  1. In Citrix Studio, select the Configuration node.
  2. In the Configuration node, select Hosting.
  3. Select an Azure-related connection to edit it.
  4. In the Edit Connection screen, click Advanced.
  5. In the Advanced screen, use the configuration options to specify the number of simultaneous actions, simultaneous virtual disk updates, maximum new actions per minute, and any additional connection options.

Azure throttling

MCS supports 500 maximum concurrent operations by default. You can use the PowerShell information to set the maximum number of concurrent operations.

Use the PowerShell property, MaximumConcurrentProvisioningOperations, to specify the maximum number of concurrent Azure provisioning operations. When using this property in the provisioning scheme, consider:

  • MCS supports 500 maximum concurrent operations by default, using the custom properties parameter MaximumConcurrentProvisioningOperations.
  • Configure the MaximumConcurrentProvisioningOperations parameter using the PowerShell command Set-ProvScheme.

Azure resource groups

Azure provisioning resource groups provide a way to provision the VMs that provide applications and desktops to users. You can add existing empty Azure resource groups when you create an MCS machine catalog in Studio, or have new resource groups created for you. For information about Azure resource groups, see the Microsoft documentation.

Azure Resource Group Usage

There is no limit on the number of virtual machines, managed disks, snapshots, and images per Azure Resource Group. (The limit of 240 VMs per 800 managed disks per Azure Resource Group has been removed.)

  • When using a full scope service principal to create a machine catalog, MCS creates only one Azure Resource Group and uses that group for the catalog.
  • When using a narrow scope service principal to create a machine catalog, you must supply an empty, pre-created Azure Resource Group for the catalog.

Azure server side encryption

Citrix Virtual Apps and Desktops service supports customer-managed encryption keys for Azure managed disks through Azure Key Vault. With this support you can manage your organizational and compliance requirements by encrypting the managed disks of your machine catalog using your own encryption key. For more information, see Server-side encryption of Azure Disk Storage.

When using this feature for managed disks:

  • To change the key that the disk is encrypted with, you change the current key in the DiskEncryptionSet. All resources associated with that DiskEncryptionSet change to be encrypted with the new key.

  • When you disable or delete your key, any VMs with disks using that key automatically shutdown. After shutting down, the VMs are not usable unless the key is enabled again or you assign a new key. Any catalog using the key cannot be powered on, and you cannot add VMs to it.

Important considerations when using customer-managed encryption keys

Consider the following when using this feature:

  • All resources related to your customer-managed keys (Azure Key Vaults, disk encryption sets, VMs, disks, and snapshots) must reside in the same subscription and region.

  • Once you have enabled the customer-managed encryption key you cannot disable it later. If you want to disable or remove the customer-managed encryption key, copy all the data to a different managed disk that is not using the customer-managed encryption key.

  • Disks created from encrypted custom images using server-side encryption and customer-managed keys must be encrypted using the same customer-managed keys. These disks must be in the same subscription.

  • Snapshots created from disks that are encrypted with server-side encryption and customer-managed keys must be encrypted with the same customer-managed keys.

  • Disks, snapshots, and images encrypted with customer-managed keys cannot move to another resource group and subscription.

  • Managed disks currently or previously encrypted using Azure Disk Encryption cannot be encrypted using customer-managed keys.

  • You can only create up to 50 disk encryption sets per region, per subscription.

Note:

See Quickstart: Create a Key Vault using the Azure portal for information on configuring Azure server side encryption.

Use Azure Shared Image Gallery as a published image repository for MCS provisioned machines in Azure. You can store a published image in the gallery to accelerate the creation and hydration of OS disks, improving boot and application launch times for non-persistent VMs. Shared image gallery contains the following three elements:

  • Gallery. Images are stored here. MCS creates one gallery for each machine catalog.
  • Gallery Image Definition. This definition includes information (operating system type and state, Azure region) about the published image. MCS creates one image definition for each image created for the catalog.
  • Gallery Image Version. Each image in a Shared Image Gallery can have multiple versions, and each version can have multiple replicas in different regions. Each replica is a full copy of the published image. Citrix Virtual Apps and Desktops service creates one Standard_LRS image version (version 1.0.0) for each image with the appropriate number of replicas in the catalog’s region, based on the number of machines in the catalog, the configured replica ratio, and the configured replica maximum.

Note:

Shared Image Gallery functionality only works with managed disks. It is not available for legacy machine catalogs.

For more information, see Azure shared image gallery overview.

Use the New-ProvScheme command to create a provisioning scheme with Shared Image Gallery support. Use the Set-ProvScheme command to enable or disable this feature for a provisioning scheme and to change the replica ratio and replica maximum values.

Three custom properties were added to provisioning schemes to support the Shared Image Gallery feature:

UseSharedImageGallery

  • Defines whether to use the Shared Image Gallery to store the published images. If set to True, the image is stored as a Shared Image Gallery image, otherwise the image is stored as a snapshot.
  • Valid values are True and False.
  • If the property is not defined, the default value is False.

SharedImageGalleryReplicaRatio

  • Defines the ratio of machines to gallery image version replicas.
  • Valid values are integer numbers greater than 0.
  • If the property is not defined, default values are used. The default value for persistent OS disks is 1000 and the default value for non-persistent OS disks is 40.

SharedImageGalleryReplicaMaximum

  • Defines the maximum number of replicas for each gallery image version.
  • Valid values are integer numbers greater than 0.
  • If the property is not defined, the default value is 10.
  • Azure currently supports up to 10 replicas for a gallery image single version. If the property is set to a value greater than that supported by Azure, MCS attempts to use the specified value. Azure generates an error, which MCS logs then leaves the current replica count unchanged.

Tip:

When using Shared Image Gallery to store a published image for MCS provisioned catalogs, MCS sets the gallery image version replica count based on the number of machines in the catalog, the replica ratio, and the replica maximum. The replica count is calculated by dividing the number of machines in the catalog by the replica ratio (rounding up to the nearest integer value) and then capping the value at the maximum replica count. For example, with a replica ratio of 20 and a maximum of 5, 0–20 machines have one replica created, 21–40 have 2 replicas, 41–60 have 3 replicas, 61–80 have 4 replicas, 81+ have 5 replicas.

The existing machine catalog uses Shared Image Gallery. Use the Set-ProvScheme command to update the custom properties for all existing machines in the catalog and any future machines:

Set-ProvScheme -ProvisioningSchemeName catalog-name -CustomProperties '<CustomProperties xmlns="http://schemas.citrix.com/2014/xd/machinecreation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <Property xsi:type="StringProperty" Name="StorageAccountType" Value="Standard_LRS"/> <Property xsi:type="StringProperty" Name="UseManagedDisks" Value="True"/> <Property xsi:type="StringProperty" Name="UseSharedImageGallery" Value="True"/> <Property xsi:type="IntProperty" Name="SharedImageGalleryReplicaRatio" Value="30"/> <Property xsi:type="IntProperty" Name="SharedImageGalleryReplicaMaximum" Value="20"/></CustomProperties>'

For this use case:

  1. Run Set-ProvScheme with the UseSharedImageGallery flag set to True. Optionally include the SharedImageGalleryReplicaRatio and SharedImageGalleryReplicaMaximum properties.
  2. Update the catalog.
  3. Power cycle the machines to force an update.

For example:

Set-ProvScheme -ProvisioningSchemeName catalog-name -CustomProperties '<CustomProperties xmlns="http://schemas.citrix.com/2014/xd/machinecreation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <Property xsi:type="StringProperty" Name="StorageAccountType" Value="Standard_LRS"/> <Property xsi:type="StringProperty" Name="UseManagedDisks" Value="True"/> <Property xsi:type="StringProperty" Name="UseSharedImageGallery" Value="True"/> <Property xsi:type="IntProperty" Name="SharedImageGalleryReplicaRatio" Value="30"/> <Property xsi:type="IntProperty" Name="SharedImageGalleryReplicaMaximum" Value="20"/></CustomProperties>'

Tip:

The parameters SharedImageGalleryReplicaRatio and SharedImageGalleryReplicaMaximum are not required. After the Set-ProvScheme command completes the Shared Image Gallery image has not yet been created. Once the catalog is configured to use the gallery, the next catalog update operation stores the published image in the gallery. The catalog update command creates the gallery, the gallery image, and the image version. Power cycling the machines updates them, at which point the replica count is updated, if appropriate. From that time, all existing non-persistent machines are reset using the Shared Image Gallery image and all newly provisioned machines are created using the image. The old snapshot is cleaned up automatically within a few hours.

For this use case:

  1. Run Set-ProvScheme with the UseSharedImageGallery flag set to False or not defined.
  2. Update the catalog.
  3. Power cycle the machines to force an update.

For example:

Set-ProvScheme -ProvisioningSchemeName catalog-name -CustomProperties '<CustomProperties xmlns="http://schemas.citrix.com/2014/xd/machinecreation" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> <Property xsi:type="StringProperty" Name="StorageAccountType" Value="Standard_LRS"/> <Property xsi:type="StringProperty" Name="UseManagedDisks" Value="True"/> <Property xsi:type="StringProperty" Name="UseSharedImageGallery" Value="False"/></CustomProperties>'

Tip:

Unlike updating from a snapshot to a Shared Image Gallery catalog, the custom data for each machine is not yet updated to reflect the new custom properties. Run the following command to see the original Shared Image Gallery custom properties: Get-ProvVm -ProvisioningSchemeName catalog-name. After the Set-ProvScheme command completes the image snapshot has not yet been created. Once the catalog is configured to not use the gallery, the next catalog update operation stores the published image as a snapshot. From that time, all existing non-persistent machines are reset using the snapshot and all newly provisioned machines are created from the snapshot. Power cycling the machines updates them, at which point the custom machine data is updated to reflect that UseSharedImageGallery is set to False. The old Shared Image Gallery assets (gallery, image, and version) are automatically cleaned up within a few hours.

Provision machines into specified availability zones

You can provision machines into a specific availability zone in Azure environments. Using PowerShell, you can view the service offering inventory items using Get-Item. For example, to view the Eastern US region Standard_B1ls service offering:

$serviceOffering = Get-Item -path "XDHyp:\Connections\my-connection-name\East US.region\serviceoffering.folder\Standard_B1ls.serviceoffering"

To view the zones, use the AdditionalData parameter for the item:

$serviceOffering.AdditionalData

If Availability Zones are not specified, there is no change in how machines are provisioned.

Note:

Availability Zones functionality is only supported for managed disks. It is not available for legacy machine catalogs.

Configuring availability zones

To configure this feature a custom property called Zones was added to the New-ProvScheme operation to support Availability Zones. The Zones property defines a list of Availability Zones to provision machines into. These zones can include one or more Availability Zones. For example, <Property xsi:type="StringProperty" Name="Zones" Value="1, 3"/> for Zones 1 and 3.

Use the Set-ProvScheme command to update the zones for a provisioning scheme.

If an invalid zone is provided, the provisioning scheme is not updated, and an error message appears providing instructions on how to fix the invalid command.

Tip:

If you specify an invalid custom property, the provisioning scheme is not updated and a relevant error message appears.

Requirements

  • If you want the Citrix Virtual Apps and Desktops service to create resource groups for each MCS catalog, the Azure service principal associated with the host connection must have permission to create and delete resource groups. If you want the Citrix Virtual Apps and Desktops service to use existing empty resource groups, the Azure service principal associated with the host connection must have Contributor permission on those empty resource groups.
  • When you create a host connection in Studio using the Create new option, the created service principal has subscription scope contribute permissions. Alternatively, you can use the Use existing option to create the connection, and provide the details of an existing subscription scope service principal. If you use the Create new option and create the Service Principal in Studio, it has the needed permissions to create and delete new resource groups or provision into existing empty resource groups.
  • Narrow scope service principals must be created using PowerShell. Also, when using a narrow scope service principal, you must use PowerShell or the Azure portal to create empty resource groups in the same region as your host connection for each catalog where MCS provisions VMs. For instructions, see the blog post https://www.citrix.com/blogs/2016/11/09/azure-role-based-access-control-in-xenapp-xendesktop/.)

If you are using a narrow scope service principal for the host connection and don’t see your image resource group on the Master Image page of the catalog creation wizard, it is probably because the narrow scope service principal you are using doesn’t have the permission Microsoft.Resources/subscriptions/resourceGroups/read to list the image resource group. Close the wizard, update the service principal with the permission (see the blog post for instructions), and then restart the wizard. The update in Azure can take up to 10 minutes to appear in Studio.

Configure resource groups for a machine catalog in Studio

The Resource Groups page in the catalog creation wizard allows you to choose whether to create resource groups or use existing groups. See Create a machine catalog using an Azure Resource Manager master image.

What happens to resource groups when you delete a machine catalog. If you let the Citrix Virtual Apps and Desktops service create resource groups when you create the machine catalog, and then later delete the catalog, those resource groups, and other resources in those resource groups are also deleted.

If you use existing resource groups when you create the machine catalog, and then later delete the catalog, all resources in those resource groups are deleted, but the resource groups are not deleted.

Considerations and limitations

When you use existing resource groups, the list of available resource groups on the Resource Groups page in the catalog creation wizard does not auto-refresh. So, if you have that wizard page open and create or add permissions to resource groups in Azure, the changes are not reflected in the wizard’s list. To see the latest changes, go back to the Machine Management page in the wizard and reselect the resources associated with the host connection. Or, close and restart the wizard. It can take up to 10 minutes for changes made in Azure to appear in Studio.

If your connection uses a service principal that can access empty resource groups in various regions, they appear in the available list. Be sure to choose resource groups in the same region where you’re creating the machine catalog.

Troubleshooting

  • Resource groups don’t appear in the list on the Resource Groups page of the catalog creation wizard.

    The service principal must have appropriate permissions applied to the resource groups you want to appear in the list. See Requirements.

More information