Citrix Virtual Apps and Desktops service

Create machine catalogs

Collections of physical or virtual machines are managed as a single entity called a machine catalog. All the machines in a catalog have the same type of operating system: multi-session OS or single-session OS. A catalog containing multi-session OS machines can contain either Windows or Linux machines, not both.


If you are using Azure Resource Manager to host your resources, you can optionally use the Quick Deploy deployment method, instead of using Studio as described in this article. For details, see Quick Deploy.

Studio guides you to create the first machine catalog. After you create the first catalog, Studio guides you to create the first delivery group. Later, you can change the catalog you created, and create more catalogs.


When you create a catalog of VMs, you specify how to provision those VMs. You can use Citrix tools such as Machine Creation Services (MCS) or Citrix Provisioning. Or, you can use your own tools to provide machines.

  • If you use Citrix Provisioning to create machines, see the Citrix Provisioning documentation for instructions.
  • If you use MCS to provision VMs, you provide a master image (or snapshot) to create identical VMs in the catalog. Before you create the catalog, you first use hypervisor or cloud service tools to create and configure the master image. This process includes installing a Virtual Delivery Agent (VDA) on the image. Then you create the machine catalog in the Studio management console. You select that image (or a snapshot of an image), specify the number of VMs to create in the catalog, and configure additional information.
  • If your machines are already available (so you do not need master images), you must still create one or more machine catalogs for those machines.

When using MCS to create the first catalog, you specify a host connection that you created previously. Later (after you create your first catalog and delivery group), you can change information about that connection or create more connections.

If a Cloud Connector is not operating properly, MCS provisioning operations (such as catalog updates) take much longer than usual, and Studio performance degrades significantly.

RDS license check

Creation of a machine catalog containing Windows multi-session OS machines includes an automatic check for valid Microsoft RDS licenses. Studio searches the catalog for a powered-on and registered machine to perform the check on.

  • If a powered-on and registered machine cannot be found, a warning is displayed, explaining that the RDS licensing check cannot be performed.
  • If a machine is found and an error is detected, Studio displays a warning message for the catalog containing the detected issue. To remove an RDS license warning from a catalog (so that it no longer appears in the Studio display), select the catalog. Click Remove RDS license warning in the Actions pane. When prompted, confirm the action.

VDA registration

A VDA must be registered with a Cloud Connector to be considered when launching brokered sessions. Unregistered VDAs can result in underutilization of otherwise available resources. There are various reasons a VDA might not be registered, many of which you can troubleshoot. Studio provides troubleshooting information in the catalog creation wizard, and after you add a catalog to a delivery group.

In the catalog creation wizard, after you add existing machines, the list of computer account names indicates whether each machine is suitable for adding to the catalog. Hover over the icon next to each machine to display an informative message about that machine.

If the message identifies a problematic machine, you can either remove that machine (using the Remove button), or add the machine. For example, if a message indicates that information cannot be obtained about a machine (perhaps because it had never registered), you might choose to add the machine anyway.

For more information about VDA registration troubleshooting, see CTX136668.

MCS catalog creation summary

Here’s a brief overview of default MCS actions after you provide information in the catalog creation wizard.

  • If you selected a master image (rather than a snapshot), MCS creates a snapshot.
  • MCS creates a full copy of the snapshot and places the copy on each storage location defined in the host connection.
  • MCS adds the machines to Active Directory, which creates unique identities.
  • MCS creates the number of VMs specified in the wizard, with two disks defined for each VM. In addition to the two disks per VM, a master is also stored in the same storage location. If you have multiple storage locations defined, each gets the following disk types:
    • The full copy of the snapshot (noted above), which is read-only and shared across the just-created VMs.
    • A unique 16 MB identity disk that gives each VM a unique identity. Each VM gets an identity disk.
    • A unique difference disk to store writes made to the VM. This disk is thin provisioned (if supported by the host storage) and increases to the maximum size of the master image, if necessary. Each VM gets a difference disk. The difference disk holds changes made during sessions. It is permanent for dedicated desktops. For pooled desktops, it is deleted and a new one created after each restart.

Alternatively, when creating VMs to deliver static desktops, you can specify (on the Machines page of the catalog creation wizard) thick (full copy) VM clones. Full clones do not require retention of the master image on every data store. Each VM has its own file.

MCS storage considerations

There are many factors when deciding on storage solutions, configurations, and capacities for MCS. The following information provides proper considerations for storage capacity:

Capacity considerations:

  • Disks

    The Delta or Differencing (Diff) Disks consume the largest amount of space in most MCS deployments for each VM. Each VM created by MCS is given at minimum 2 disks upon creation.

    • Disk0 = Diff Disk: contains the OS when copied from the Master Base Image.
    • Disk1 = Identity Disk: 16 MB - contains Active Directory data for each VM.

    As the product evolves, you might have to add more disks to satisfy certain use cases and feature consumption. For example:

    • MCS Storage Optimization creates a write cache style disk for each VM.
    • MCS added the ability to use full clones as opposed to the Delta disk scenario described in the previous section.

    Hypervisor features might also enter into the equation. For example:

    • Citrix Hypervisor IntelliCache creates a Read Disk on local storage for each Citrix Hypervisor. This option saves on IOPS against the master image which might be held on the shared storage location.
  • Hypervisor overhead

    Different hypervisors utilize specific files that create overhead for VMs. Hypervisors also use storage for management and general logging operations. Calculate space to include overhead for:

    • Log files
    • Hypervisor specific files. For example:
      • VMware adds more files to the VM storage folder. See VMware Best Practices.
      • Calculate your total virtual machine size requirements. Consider a virtual machine containing 20 GB for the virtual disk, 16 GB for the swap file, and 100 MB for log files consuming 36.1 GB total.
    • Snapshots for XenServer; Snapshots for VMware.
  • Process overhead

    Creating a catalog, adding a machine, and updating a catalog have unique storage implications. For example:

    • Initial catalog creation requires a copy of the base disk to be copied to each storage location.
    • Adding a machine to a catalog does not require copying of the base disk to each storage location. Catalog creation varies based on the features selected.
    • Updating the catalog to create an extra base disk on each storage location. Catalog updates also experience a temporary storage peak where each VM in the catalog has 2 Diff disks for a certain amount of time.

More considerations:

  • RAM sizing: Affects the size of certain hypervisor files and disks, including I/O optimization disks, write cache, and snapshot files.
  • Thin / Thick provisioning: NFS storage is preferred due to the thin provisioning capabilities.

Machine Creation Services (MCS) storage optimization

With the Machine Creation Services (MCS) storage optimization feature, referred to as MCS I/O:

  • The write cache container is file-based, the same functionality found in Citrix Provisioning. For example, the Citrix Provisioning write cache file name is D:\vdiskdif.vhdx and the MCS I/O write cache file name is D:\mcsdif.vhdx.
  • Achieve diagnostic improvements by including support for a Windows crash dump file written to the write cache disk.
  • MCS I/O retains the technology cache in RAM with overflow to hard disk to provide the most optimal multi-tier write cache solution. This functionality allows an administrator to balance between the cost in each tier, RAM and disk, and performance to meet the desired workload expectation.

Updating the write cache method from disk-based to file-based requires the following changes:

  1. MCS I/O no longer supports RAM only cache. Specify a disk size in Citrix Studio during machine catalog creation.
  2. The VM write cache disk is created and formatted automatically when booting a VM for the first time. Once the VM is up, the write cache file mcsdif.vhdx is written into the formatted volume MCSWCDisk.
  3. The pagefile is redirected to this formatted volume, MCSWCDisk. As a result, this disk size considers the total amount of disk space. It includes the delta between the disk size and the generated workload plus the pagefile size. This is typically associated with VM RAM size.

Enabling MCS storage optimization updates

To enable MCS I/O storage optimization functionality, upgrade the Delivery Controller and the VDA to the latest version of Citrix Virtual Apps and Desktops.


If you upgrade an existing deployment which has MCS I/O enabled, no additional configuration is required. The VDA and the Delivery Controller upgrade handle the MCS I/O upgrade.

When creating a machine catalog, the administrator can configure the RAM and disk size, as illustrated below:

Machine catalog setup

Using PowerShell to create a catalog with persistent write-back cache disk

To configure a catalog with persistent write-back cache disk, use the PowerShell parameter New-ProvScheme CustomProperties. This parameter supports an extra property, PersistWBC, used to determine how the write-back cache disk persists for MCS provisioned machines. The PersistWBC property is only used when the UseWriteBackCache parameter is specified, and when the WriteBackCacheDiskSize parameter is set to indicate that a disk is created.

Examples of properties found in the CustomProperties parameter before supporting PersistWBC include:

<CustomProperties xmlns="" xmlns:xsi="">
<Property xsi:type="StringProperty" Name="UseManagedDisks" Value="true" />
<Property xsi:type="StringProperty" Name="StorageAccountType" Value="Premium_LRS" />
<Property xsi:type="StringProperty" Name="ResourceGroups" Value="benvaldev5RG3" />

When using these properties, consider that they contain default values if the properties are omitted from the CustomProperties parameter. The PersistWBC property has two possible values: true or false.

Setting the PersistWBC property to true does not delete the write-back cache disk when the Citrix Virtual Apps and Desktops administrator shuts down the machine using Citrix Studio.

Setting the PersistWBC property to false deletes the write-back cache disk when the Citrix Virtual Apps and Desktops administrator shuts down the machine using Citrix Studio.


If the PersistWBC property is omitted, the property defaults to false and the write-back cache is deleted when the machine is shutdown using Citrix Studio.

For example, using the CustomProperties parameter to set PersistWBC to true:

<CustomProperties xmlns="" xmlns:xsi="">
<Property xsi:type="StringProperty" Name="UseManagedDisks" Value="true" />
<Property xsi:type="StringProperty" Name="StorageAccountType" Value="Premium_LRS" />
<Property xsi:type="StringProperty" Name="ResourceGroups" Value="benvaldev5RG3" />
<Property xsi:type="StringProperty" Name="PersistWBC" Value="true" />


The PersistWBC property can only be set using the New-ProvScheme PowerShell cmdlet. Attempting to alter the CustomProperties of a provisioning scheme after creation has no impact on the machine catalog and the persistence of the write-back cache disk when a machine is shut down.

For example, set New-ProvSchemeto use the write-back cache while setting the PersistWBC property to true:

-CustomProperties "<CustomProperties xmlns=`"`" xmlns:xsi=`"`"><Property xsi:type=`"StringProperty`" Name=`"UseManagedDisks`" Value=`"true`" /><Property xsi:type=`"StringProperty`" Name=`"StorageAccountType`" Value=`"Premium_LRS`" /><Property xsi:type=`"StringProperty`" Name=`"ResourceGroups`" Value=`"benvaldev5RG3`" /><Property xsi:type=`"StringProperty`" Name=`"PersistWBC`" Value=`"true`" /></CustomProperties>"
-HostingUnitName "adSubnetScale1"
-IdentityPoolName "BV-WBC1-CAT1"
-MasterImageVM "XDHyp:\HostingUnits\adSubnetScale1\image.folder\GoldImages.resourcegroup\W10MCSIO-01_OsDisk_1_a940e6f5bab349019d57ccef65d2c7e3.manageddisk"
-NetworkMapping @{"0"="XDHyp:\HostingUnits\adSubnetScale1\\virtualprivatecloud.folder\CloudScale02.resourcegroup\adVNET.virtualprivatecloud\"}
-ProvisioningSchemeName "BV-WBC1-CAT1"
-ServiceOffering "XDHyp:\HostingUnits\adSubnetScale1\serviceoffering.folder\Standard_D2s_v3.serviceoffering"
-WriteBackCacheDiskSize 127
-WriteBackCacheMemorySize 256

Improve boot performance

You can improve boot performance for Azure managed disks when MCSIO is enabled. Use the PowerShell PersistOSDisk custom property in the New-ProvScheme command to configure this feature. Options associated with New-ProvScheme include:

<CustomProperties xmlns="" xmlns:xsi="">
<Property xsi:type="StringProperty" Name="UseManagedDisks" Value="true" />
<Property xsi:type="StringProperty" Name="StorageAccountType" Value="Premium_LRS" />
<Property xsi:type="StringProperty" Name="Resource``````````````Groups" Value="benvaldev5RG3" />
<Property xsi:type="StringProperty" Name="PersistOsDisk" Value="true" />

To enable this feature, set thePersistOSDisk custom property to true. For example:

-CustomProperties "<CustomProperties xmlns=`"`" xmlns:xsi=`"`"><Property xsi:type=`"StringProperty`" Name=`"UseManagedDisks`" Value=`"true`" /><Property xsi:type=`"StringProperty`" Name=`"StorageAccountType`" Value=`"Premium_LRS`" /><Property xsi:type=`"StringProperty`" Name=`"ResourceGroups`" Value=`"benvaldev5RG3`" /><Property xsi:type=`"StringProperty`" Name=`"PersistOsDisk`" Value=`"true`" /></CustomProperties>"
-HostingUnitName "adSubnetScale1"
-IdentityPoolName "BV-WBC1-CAT1"
-MasterImageVM "XDHyp:\HostingUnits\adSubnetScale1\image.folder\GoldImages.resourcegroup\W10MCSIO-01_OsDisk_1_a940e6f5bab349019d57ccef65d2c7e3.manageddisk"
-NetworkMapping @{"0"="XDHyp:\HostingUnits\adSubnetScale1\\virtualprivatecloud.folder\CloudScale02.resourcegroup\adVNET.virtualprivatecloud\"}
-ProvisioningSchemeName "BV-WBC1-CAT1"
-ServiceOffering "XDHyp:\HostingUnits\adSubnetScale1\serviceoffering.folder\Standard_D2s_v3.serviceoffering"
-WriteBackCacheDiskSize 127
-WriteBackCacheMemorySize 256

AWS dedicated host tenancy support

You can use MCS to provision AWS dedicated hosts. An administrator can create a catalog of machines with host tenancy defined through PowerShell.

An Amazon [EC2] dedicated host is a physical server with [EC2] instance capacity that is fully dedicated, allowing you to use existing per-socket, or per-VM software licenses.

Dedicated hosts have preset utilization based on instance type. For example, a single allocated dedicated host of C4 Large instance types is limited to running 16 instances. See the AWS site for more information.

The requirements for provisioning to AWS hosts include:

  • An imported BYOL (bring your own license) image (AMI). With dedicated hosts, use and manage your existing licenses.
  • An allocation of dedicated hosts with sufficient utilization to satisfy provisioning requests.
  • enable auto-placement.

To provision to a dedicated host in AWS using PowerShell, use the New-ProvScheme cmdlet with the parameter TenancyType set to Host.

Refer to the Citrix Developer Documentation for more information.

AWS instance property capturing

When you create a catalog to provision machines using Machine Creation Services (MCS) in AWS, you select an AMI to represent the master/golden image of that catalog. From that AMI, MCS uses a snapshot of the disk. In previous releases, if you wanted roles and/or tags on your machines you would use the AWS console to set them individually.

To improve this process, MCS reads properties from the instance from which the AMI was taken and applies the Identity Access Management (IAM) role and tags of the machine to the machines provisioned for a given catalog. When using this optional feature, the catalog creation process finds the selected AMI source instance, reading a limited set of properties. These properties are then stored in an AWS Launch Template, which is used to provision machines for that catalog. Any machine in the catalog inherits the captured instance properties.

Captured properties include:

  • IAM roles – applied to provisioned instances
  • Tags - applied to provisioned instances, their disk, and NICs. These tags are applied to transient Citrix resources, including: S3 bucket and objects, volume and worker resources, and AMIs, snapshots, and launch templates.


The tagging of transient Citrix resources is optional and is configurable using the custom property AwsOperationalResourcesTagging.

Capturing the AWS instance property

You can use this feature by specifying a custom property, AwsCaptureInstanceProperties, when creating a provisioning scheme for an AWS hosting connection:

New-ProvScheme -CustomProperties “AwsCaptureInstanceProperties,true” …<standard provscheme parameters

To use this feature, you must specify a broader set of permissions for the AWS service key. These permissions include:

  • ec2:AssociateIamInstanceProfile
  • ec2:CreateLaunchTemplate
  • ec2:DeleteLaunchTemplate
  • ec2:DeleteTags
  • ec2:DisassociateIamInstanceProfile
  • ec2:DescribeIamInstanceProfileAssociations
  • ec2:DescribeLaunchTemplates
  • ec2:DescribeLaunchTemplateVersions
  • ec2:DescribeSnapshots
  • ec2:DescribeTags
  • iam:PassRole
  • s3:PutBucketTagging
  • s3:PutObjectTagging

Refer to the Citrix Developer Documentation for more information.

AWS operational resource tagging

An Amazon Machine Image (AMI) represents a type of virtual appliance used to create a virtual machine within the Amazon Cloud environment, commonly referred to as EC2. You use an AMI to deploy services that use the EC2 environment. When you create a catalog to provision machines using MCS for AWS, you select the AMI to act as the golden image for that catalog.


Creating catalogs by capturing an instance property and launch template is required for using operational resource tagging. For details, see the preceding section AWS instance property capturing.

To create an AWS catalog, you must first create an AMI for the instance you want to be the golden image. MCS reads the tags from that instance and incorporates them into the launch template. The launch template tags are then applied to all Citrix resources created in your AWS environment, including:

  • Virtual Machines
  • VM disks
  • VM network interfaces
  • S3 buckets
  • S3 objects
  • Launch templates
  • AMIs

Tagging an operational resource

To use PowerShell to tag resources:

  1. Open a PowerShell window from the DDC host.
  2. Run the command asnp citrix to load Citrix-specific PowerShell modules.

To tag a resource for a provisioned VM, use the new custom property AwsOperationalResourcesTagging. The syntax for this property is:

New-ProvScheme -CustomProperties “AwsCaptureInstanceProperties,true; AwsOperationalResourcesTagging,true” …<standard provscheme parameters>

To use the AwsOperationalResourcesTagging custom property, ensure that the following new permissions exist for the AWS service key:

  • ec2:CreateTags
  • ec2:DeleteTags
  • ec2:DescribeTags
  • s3:PutBucketTagging
  • s3:PutObjectTagging

Set these permissions in the IAM section of the AWS Management Console:

  1. In the Summary panel, select the Permissions tab.
  2. Click Add permissions.

Identity and Access Management (IAM)

In the Add Permissions to screen, grant permissions:

Grant permissions for IAM policies

Use the following as an example in the JSON tab:

JSON example


The noted JSON example may not include all the permissions for your environment. See How to Define Identity Access Management Permissions Running Citrix Virtual Apps and Desktops on Amazon Web Services for more information.

Prepare a master image on the hypervisor or cloud service

The master image contains the operating system, non-virtualized applications, VDA, and other software.

Good to know:

  • A master image might also be known as a clone image, golden image, base VM, or base image. Host vendors and cloud service providers may use different terms.
  • When using Citrix Provisioning, you can use a master image or a physical computer as the master target device. Citrix Provisioning uses different terminology than MCS to refer to images; see the Citrix Provisioning](/en-us/provisioning.html) documentation for details.
  • Ensure that the hypervisor or cloud service has enough processors, memory, and storage to accommodate the number of machines created.
  • Configure the correct amount of hard disk space needed for desktops and applications. That value cannot be changed later or in the machine catalog.
  • Remote PC Access machine catalogs do not use master images.
  • Microsoft KMS activation considerations when using MCS: If your deployment includes 7.x VDAs with a XenServer 6.1 or 6.2, vSphere, or Microsoft System Center Virtual Machine Manager host, you do not need to manually rearm Microsoft Windows or Microsoft Office.

Install and configure the following software on the master image:

  • Integration tools for your hypervisor (such as Citrix VM Tools, Hyper-V Integration Services, or VMware tools). If you omit this step, applications and desktops might not function correctly.
  • A VDA. Citrix recommends installing the latest version to allow access to the newest features. Failure to install a VDA on the master image causes the catalog creation to fail.
  • Third-party tools as needed, such as antivirus software or electronic software distribution agents. Configure services with settings that are appropriate for users and the machine type (such as updating features).
  • Third-party applications that you are not virtualizing. Citrix recommends virtualizing applications. Virtualizing reduces costs by eliminating having to update the master image after adding or reconfiguring an application. Also, fewer installed applications reduce the size of the master image hard disks, which saves storage costs.
  • App-V clients with the recommended settings, if you plan to publish App-V applications. The App-V client is available from Microsoft.
  • When using MCS, if you localize Microsoft Windows, install the locales and language packs. During provisioning, when a snapshot is created, the provisioned VMs use the installed locales and language packs.


If you are using Citrix Provisioning or MCS, do not run Sysprep on master images.

To prepare a master image:

  1. Using your hypervisor’s management tool, create a master image and then install the operating system, plus all service packs and updates. Specify the number of vCPUs. You can also specify the vCPU value if you create the machine catalog using PowerShell. You cannot specify the number of vCPUs when creating a catalog using Studio. Configure the amount of hard disk space needed for desktops and applications. That value cannot be changed later or in the catalog.
  2. Ensure that the hard disk is attached at device location 0. Most standard master image templates configure this location by default, but some custom templates might not.
  3. Install and configure the software listed above on the master image.
  4. When using Citrix Provisioning, create a VHD file for the virtual disk from your master target device before you join the master target device to a domain. See the Citrix Provisioning documentation for details.
  5. If you are not using MCS, join the master image to the domain where applications and desktops are members. Ensure that the master image is available on the host where the machines are created. If you are using MCS, joining the master image to a domain is not required. The provisioned machines are joined to the domain specified in the catalog creation wizard.
  6. Citrix recommends that you create and name a snapshot of your master image so that it can be identified later. If you specify a master image rather than a snapshot when creating a catalog, Studio creates a snapshot, but you cannot name it.

Start creating the catalog

Before creating a catalog:

  • Review this section to learn about the choices you make and information you supply.
  • Ensure that you have created a connection to the hypervisor, cloud service, other resource that hosts your machines.
  • If you have created a master image to provision machines, ensure that you have installed a VDA on that image.

To start the catalog creation wizard:

  1. Sign in to Citrix Cloud. In the upper left menu, select My Services > Virtual Apps and Desktops.
  2. Click Manage.
  3. If this is the first catalog being created, Studio guides you to the correct selection (such as “Set up the machines and create machine catalogs to run apps and desktops.”). The catalog creation wizard opens and walks you through the items described below.

If you already created a catalog and want to create another, select Machine Catalogs in the Studio navigation pane. Then select Create Machine Catalog in the Actions pane.

The wizard walks you through the pages described below. The pages you see may differ, depending on the selections you make, and the connection (to a host) you use. Hosts / virtualization resources lists information sources for the supported host types.

Operating system

Each catalog contains machines of only one type:

  • Multi-session OS: A multi-session OS catalog provides hosted shared desktops. The machines can be running supported versions of the Windows or Linux operating systems, but the catalog cannot contain both.
  • Single-session OS: A single-session OS catalog provides VDI desktops that you can assign to various different users.
  • Remote PC Access: A Remote PC Access catalog provides users with remote access to their physical office desktop machines. Remote PC Access does not require a VPN to provide security.

Machine management

This page does not appear when you are creating a Remote PC Access catalog.

The Machine Management page indicates how machines are managed and which tool you use to deploy machines.

Choose if machines in the catalog will be power managed through Studio.

  • Machines are power managed through Studio or provisioned through a cloud environment, for example, VMs or blade PCs. This option is available only if you already configured a connection to a hypervisor or cloud service.
  • Machines are not power managed through Studio, for example, physical machines.

If you indicated that machines are power managed through Studio or provisioned through a cloud environment, choose which tool to use to create VMs.

  • Citrix Machine Creation Services (MCS): Uses a master image to create and manage virtual machines. Machine catalogs in cloud environments use MCS. MCS is not available for physical machines.
  • Citrix Provisioning: Manages target devices as a device collection. A Citrix Provisioning virtual disk imaged from a master target device delivers desktops and applications. This option is not available for cloud deployments.
  • Other: A tool that manages machines already in the data center. Citrix recommends that you use Microsoft System Center Configuration Manager or another third-party application to ensure that the machines in the catalog are consistent.

Desktop types (desktop experience)

This page appears only when you are creating a catalog containing single-session OS machines.

The Desktop Experience page determines what occurs each time a user logs on. Select one of:

  • Users connect to a new (random) desktop each time they log on.
  • Users connect to the same (static) desktop each time they log on.

If you choose the second option and are using Citrix Provisioning to provision the machines, you can configure how user changes to the desktop are handled:

  • Save user changes to the desktop on a separate Personal vDisk.
  • Save user changes to the desktop on the local disk.
  • Discard user changes and clear the virtual desktop when the user logs off.

Master image

This page appears only when you are using MCS to create VMs.

Select the connection to the host hypervisor or cloud service, and then select the snapshot or VM created earlier.


  • When you are using MCS or Citrix Provisioning, do not run Sysprep on master images.
  • If you specify a master image rather than a snapshot, Studio creates a snapshot, but you cannot name it.

Do not change the default minimum VDA version selection.

An error message appears if you select a snapshot or VM that is not compatible with the machine management technology you selected earlier in the wizard.

Cloud platform and service environments

When you are using a cloud service or platform to host VMs, the catalog creation wizard may contain extra pages specific to that host. For example, when using an Azure Resource Manager master image, the catalog creation wizard contains a Storage and License Types page.

For host-specific information, follow the appropriate link listed in Start creating the catalog.

Device Collection

This page appears only when using Citrix Provisioning to create VMs. It displays the device collections and the devices that have not already been added to catalogs.

Select the device collections to use. See the Citrix Provisioning documentation for details.


This page does not appear when you are creating Remote PC Access catalogs.

The title of this page depends on what you selected on the Machine Management page: Machines, Virtual Machines, or VMs and users.

  • When using MCS to create machines:

    • Specify how many virtual machines to create.
    • Choose the amount of memory (in MB) each VM has.
    • Important: Each created VM has a hard disk. Its size is set in the master image; you cannot change the hard disk size in the catalog.
    • If you indicated on the Desktop Experience page that user changes to static desktops should be saved on a separate Personal vDisk, specify the virtual disk size in GB and the drive letter.
    • If your deployment uses more than one zone (resource location), you can select a zone for the catalog.
    • If you are creating static desktop VMs, select a virtual machine copy mode. See Virtual machine copy mode.
    • If you are creating random desktop VMs that do not use personal vDisks, you can configure a cache to be used for temporary data on each machine. See Configure cache for temporary data.
  • When using Citrix Provisioning to create machines:

    The Devices page lists the machines in the device collection that you selected on the previous wizard page. You cannot add or remove machines on this page.

  • When using other tools to provide machines:

    Add (or import a list of) Active Directory machine account names. You can change the Active Directory account name for a VM after you add/import it. If you specified static machines on the Desktop Experience wizard page, you can optionally specify the Active Directory user name for each VM you add.

    After you add or import names, you can use the Remove button to delete names from the list, while you are still on this wizard page.

  • When using Citrix Provisioning or other tools (but not MCS):

    An icon and tooltip for each machine added (or imported, or from a Citrix Provisioning device collection) help identify machines that might not be eligible to add to the catalog, or be unable to register with a Cloud Connector.

Virtual machine copy mode

The copy mode you specify on the Machines page determines whether MCS creates thin (fast copy) or thick (full copy) clones from the master image. (Default = thin clones)

  • Use fast copy clones for more efficient storage use and faster machine creation.
  • Use full copy clones for better data recovery and migration support, with potentially reduced IOPS after the machines are created.

Configure cache for temporary data

Caching temporary data locally on the VM is optional. You can enable use of the temporary data cache on the machine when you use MCS to manage pooled (not dedicated) machines in a catalog. If the catalog uses a connection that specifies storage for temporary data, you can enable and configure the temporary data cache information when you create the catalog.

To enable the caching of temporary data, the VDA on each machine in the catalog must be minimum version 7.9. This feature is referred to as MCSIO.


This feature requires a current MCSIO driver. Installing this driver is an option when you install or upgrade a VDA. By default, that driver is not installed.

You specify whether temporary data uses shared or local storage when you create the connection that the catalog uses. For details, see Connections and resources. Enabling and configuring the temporary cache in the catalog includes two check boxes and values: Memory allocated to cache (MB) and Disk cache size (GB). By default, these check boxes are cleared. When you enable one or both check boxes, the default values differ according to the connection type. Generally, the default values are sufficient for most cases; however, take into account the space needed for:

  • Temporary data files created by Windows itself, including the Windows page file.
  • User profile data.
  • ShareFile data that is synced to users’ sessions.
  • Data that may be created or copied by a session user or any applications users may install inside the session.

Windows will not allow a session to use an amount of cache disk that is larger than the amount of free space on the original master image from which machines in the machine catalog are provisioned. For example, there is no benefit specifying a 20 GB cache disk if there is only 10 GB of free space on the master image.

If you enable the Disk cache size check box, temporary data is initially written to the memory cache. When the memory cache reaches its configured limit (the Memory allocated to cache value), the oldest data is moved to the temporary data cache disk.

Storage image

The memory cache is part of the total amount of memory on each machine; therefore, if you enable the Memory allocated to cache check box, consider increasing the total amount of memory on each machine.

If you clear the Memory allocated to cache check box and leave the Disk cache size check box enabled, temporary data is written directly to the cache disk, using a minimal amount of memory cache.

Changing the Disk cache size from its default value can affect performance. The size must match user requirements and the load placed on the machine.


If the disk cache runs out of space, the user’s session becomes unusable.

If you clear the Disk cache size check box, no cache disk is created. In this case, specify a Memory allocated to cache value that is large enough to hold all of the temporary data. This is feasible only if large amounts of RAM are available for allocation to each VM.

If you clear both check boxes, temporary data is not cached. It is written to the difference disk (located in the OS storage) for each VM. (This is the provisioning action in releases earlier than 7.9.)

Do not enable caching if you intend to use this catalog to create AppDisks.

You cannot change the cache values in a machine catalog after it is created.


This page does not appear when you are creating Remote PC Access catalogs.

If you plan to use multiple NICs, associate a virtual network with each card. For example, you can assign one card to access a specific secure network, and another card to access a more commonly used network. You can also add or remove NICs from this page.

Machine accounts

This page appears only when creating Remote PC Access catalogs.

Specify the Active Directory machine accounts or Organizational Units (OUs) to add that correspond to users or user groups. Do not use a forward slash (/) in an OU name.

You can choose a previously configured power management connection or elect not to use power management. If you want to use power management but a suitable connection hasn’t been configured yet, you can create that connection later and then edit the machine catalog to update the power management settings.

Computer accounts

This page appears only when using MCS to create VMs.

Each machine in the catalog must have a corresponding Active Directory computer account. Indicate whether to create accounts or use existing accounts, and the location for those accounts.

  • If you create accounts, you must have access to a domain administrator account for the domain where the machines reside.

    Specify the account naming scheme for the machines that will be created, using hash marks to indicate where sequential numbers or letters appear. Do not use a forward slash (/) in an OU name. A name cannot begin with a number. For example, a naming scheme of PC-Sales-## (with 0-9 selected) results in computer accounts named PC-Sales-01, PC-Sales-02, PC-Sales-03, and so on.

  • If you use existing accounts, either browse to the accounts or click Import and specify a .csv file containing account names. The imported file content must use the format:

    [ADComputerAccount] ADcomputeraccountname.domain

Ensure that there are enough accounts for all the machines you’re adding. Studio manages these accounts, so either allow Studio to reset the passwords for all the accounts or specify the account password, which must be the same for all accounts.

For catalogs containing physical machines or existing machines, select or import existing accounts and assign each machine to both an Active Directory computer account and to a user account.

For machines created with Citrix Provisioning, computer accounts for target devices are managed differently; see the Citrix Provisioning documentation.

Domain Credentials

Click Enter credentials and enter user credentials with sufficient permissions to create machine accounts in Active Directory.


The account you used to log into Studio is the same account you use to interact with Active Directory. When provisioning a new catalog, adding machines to a catalog, or removing a catalog and the machine names from Active Directory, a dialog appears requesting your Active Directory domain administrator credentials.

Summary, name, and description

On the Summary page, review the settings you specified. Enter a name and description for the catalog. This information appears in Studio.

When you’re done, click Finish to start the catalog creation.

More information

Where to go next

If this is the first catalog created, Studio guides you to create a delivery group.

To review the entire configuration process, see Install and configure.