Tech Brief: Citrix VDA Upgrade service

Overview

The Citrix VDA Upgrade service is a cloud-based feature of Citrix DaaS. With the VDA Upgrade service, administrators can improve operational efficiency by shifting VDA updates from manual or complex processes to automated processes that Citrix manages. With the VDA Upgrade service, administrators can:

• Quickly push VDA upgrades to persistent machines via Web Studio or PowerShell.
• Reduce time and manual work by automating VDA upgrades without the need for SCCM or custom scripts.
• Choose how to upgrade VDAs by selecting individual machines (in batches) or entire machine catalogs.
• Schedule upgrades to happen automatically when no active sessions are present.

Citrix VDA Upgrade service supports persistent machine catalogs within Citrix DaaS, including:

• Machine Creation Services persistent machines
• Manually created virtual machines
• Remote PC Access
• Windows Single session and windows multi-session persistent machines
• Windows 365 virtual machines
• Azure Active Directory or non-domain joined machines

How the VDA Upgrade Service Works

The Citrix VDA Upgrade service uses a combination of the VDA upgrade agent and the Citrix Cloud VDA Upgrade service to upgrade VDAs. The VDA Upgrade agent is an extra VDA component that needs to be selected during the VDA install or through install modification. The VDA Upgrade service is a Citrix DaaS cloud feature available through PowerShell cmdlet or Web Studio. The following workflow provides an overview of how the VDA Upgrade service works.

1. The VDA Upgrade agent (installed during VDA setup) registers the VDA version with Citrix DaaS.
2. The VDA Upgrade agent polls at given intervals for a newer version of the VDA.
3. Once Citrix DaaS publishes the latest version of the VDA, either Current Release (CR) or Long Term Service Release (LTSR), the notification is sent to Web Studio.
4. Administrators then schedule the upgrades via Web Studio or PowerShell.
5. The VDA Upgrade agent attempts to install the new version of the VDA based on the schedule selected and the availability of the VDA (no user activity).

VDA Upgrade Service Requirements

The Citrix VDA Upgrade service is available for all Citrix DaaS subscribers. The following are the additional prerequisites and requirements to use the VDA Upgrade service.

1. Citrix VDA version 2019 or later for CR and 2203 or later for LTSR.
2. Any persistent machine type currently supported.
3. VDA upgrade agent must be installed, and the service must be running.
4. The VDAs are not in use. Users must be signed off from the VDA.
5. VDAs are not in maintenance mode.
6. The [relevant URLs] (/en-us/citrix-cloud/overview/requirements/internet-connectivity-requirements.html#vda-upgrade-requirement) are added to the allow list if URL filtering exists.
7. The VDAs must belong to a Delivery Group and be registered with Citrix DaaS.
8. The functional level is appropriately set so that the VDA upgrade feature is available for use.
9. The destination VDA supports the OS of the current VDA.

Enabling VDA Upgrade Service

The VDA Upgrade feature appears as an option in Machine Catalogs when creating a catalog or editing an existing one. After enabling the feature, the admin updates machines in the catalog to the latest Current Release (CR) or Long Term Service Release (LTSR) version of the VDA.

Note

Enabling the VDA Upgrade option will not result in the sudden upgrade of the VDA for machines in the catalog. The upgrade initiation is performed as a separate task by the administrator and scheduled to run on-demand or scheduled for a later date.

VDA Upgrade Scheduling Options

Two options to start the VDA upgrade process are Upgrade Now or Upgrade Later. The same criteria for upgrading a VDA apply to both methods. The criteria for determining whether the VDA Upgrade service does the upgrade task are as follows:

• Upgrading a machine fails when:
  • The machine is not powered on. The VDA Upgrade service will not power on machines.
  • The machine has maintenance mode turned on.
  • An active or disconnected session is running on the machine.
  • The machine does not have the VDA Upgrade agent installed and running.
  • The machine cannot connect to Citrix DaaS.

Upgrade Now

Selecting the Upgrade Now option initiates the VDA Upgrade service to upgrade the VDA for individually selected VDAs or all VDAs in a Machine Catalog.

The selected duration (in hours) is a maintenance window in which the service attempts to perform the VDA upgrade if the criteria to upgrade are met. After the duration (maintenance window) expires, the VDA Upgrade service will stop its attempt at upgrading the VDA on the machine.

Upgrade Later

Selecting the Upgrade Later option initiates the VDA Upgrade service to upgrade the VDA for individually selected VDAs or all VDAs in a Machine Catalog starting on a date and time that an administrator specifies.

The selected duration (in hours) is a maintenance window in which the service attempts to perform the VDA upgrade if the criteria to upgrade are met. After the duration (maintenance window) expires, the VDA Upgrade service will stop its attempt at upgrading the VDA on the machine.

Note:

Upgrades can be scheduled for up to 7 days. Also, machines added to the catalog after applying the upgrade schedule will not be upgraded.

VDA Upgrade Indicators in Web Studio

The following table details the VDA Upgrade status icon in Web Studio when accessing the Machine Catalogs tab or viewing the VDAs in a Delivery Group.

VDA Upgrade Progress Tracking

The VDA Upgrade service reports to Web Studio the different phases a machine encounters when the VDA Upgrade service is managing updates of a VDA on a machine. The following table provides the status message and description for each upgrade phase.

VDA Upgrade Failure

If the VDA Upgrade Service or VDA Upgrade Service Agent (on the machine) encounters an issue or error that prevents a successful upgrade of the VDA, the upgrade stops, and an error is logged in Studio for the VDA. On the machine that encountered the failure, an entry with Event ID 1302 will be created in the Windows Event Viewer (Application log), providing information on the failure. The event provides the path to log files, providing much more detail.

Status and State of VDA Upgrades

Machine Catalog View

From the Machine Catalog view in Studio, ensure that the VDA Upgrade column is present. The VDA Upgrade column identifies the current VDA Upgrade status for all machines in the catalog.

Note:

The reported VDA Upgrade status is based on the VDA upgrade state of all machines in the catalog. For example, if 10 machines are in the catalog, and the VDA Upgrade has successfully updated on nine machines, the VDA Upgrade column and VDA Upgrade sections in the catalogs details tab reports a status other than Up to Date.

The details tab of a Machine Catalog provides the VDA Upgrade status of the machines in the catalog and the resulting state of VDA upgrades.

Delivery Group View

From selecting a Delivery Group in Web Studio, ensure that the VDA Upgrade column is present. The VDA Upgrade column shows the VDA Upgrade status of each machine in the Delivery Group.

Similar to the information shown for a Machine Catalog, the details tab of a machine shows the VDA Upgrade status and state of the selected machine.

VDA Upgrade Strategy

To ensure optimal performance, security, and compatibility with the latest Citrix technologies, administrators need to develop a comprehensive VDA upgrade strategy to use with the VDA Upgrade service. The following outlines key considerations and best practices for a successful VDA upgrade with the VDA Upgrade service.

1. Enable the VDA Upgrade service option for all supported Machine Catalogs. The upgrade option selected, either CR or LTSR, would follow the preference of your organization's VDA deployment policy.
2. Apply the upgrades to a subset of the VDAs within a Delivery Group for testing. Use the testing process to gather feedback and address any identified issues. If no problems are encountered during testing, schedule the upgrade for the entire catalog.
3. Deploy the VDA upgrade by defining a schedule and setting the upgrade duration for the maintenance window.

As a best practice, Citrix recommends testing the VDA upgrades using a subset of the VDAs in a close-to-production environment. Also, administrators must ensure that proper backup and OS restore points are created and scheduled as needed before the upgrade. Lastly, choose a time frame or window that has minimal impact on end users and ensure that users are logged off from the VDAs. If the VDA is logged on and/or disconnected, the VDA Upgrade service skips the machine during the upgrade.

References

Citrix DaaS - Manage Machine Catalogs

Citrix DaaS - Upgrade VDAs using the Full configuration interface

Citrix Features Explained: Citrix VDA Upgrade service

Known Issues

VDA Upgrade Troubleshooting