Updating Managed Servers

XenCenter issues notifications about available Citrix Hypervisor updates in the Updates tab on the Notifications view. Updates to Citrix Hypervisor can be delivered as one of the following types of update:

  • Hotfixes, which contain bug fixes for one or more specific issues. Hotfixes are provided for Citrix Hypervisor releases in the Long Term Service Release (LTSR) and Current Release (CR) streams.

    Hotfixes on the latest CR are available to all Citrix Hypervisor customers. However, hotfixes on previous CRs that are still in support are only available for customers with an active Citrix Customer Success Services (CSS) account.

    Hotfixes on the LTSR stream are available to customers with an active CSS account. For more information, See Licensing.

  • Cumulative Updates, which contain previously released hotfixes and might contain support for new guests and hardware. Cumulative Updates are provided for Citrix Hypervisor or XenServer releases in the LTSR stream and are available to customers with an active CSS account.

  • Current Releases, which are full versions of Citrix Hypervisor from the Current Release (CR) stream.

To provide these update notifications, XenCenter requires internet access. If your XenCenter is behind a firewall, ensure that it has access to the updates.ops.xenserver.com domain and subdomains on the citrix.com domain through the firewall.

This topic contains information about applying Citrix Hypervisor updates to your managed servers. Pay careful attention to the release note that is published with each update. Each update might have unique installation instructions, particularly regarding preparatory and post-update operations. Some updates might only be available to licensed users or to Customer Success Services customers.

In addition to Citrix Hypervisor updates, the Updates tab also notifies users about the availability of new versions of Citrix Hypervisor and new versions of XenCenter. Some new Citrix Hypervisor current releases can be applied as updates to earlier versions of Citrix Hypervisor. However, you can only reach some new releases by the upgrade process. For information about upgrading Citrix Hypervisor, see Upgrading Managed Servers. To update your XenCenter to a newer version, see Updating XenCenter. For information about installing supplemental packs, see Installing Supplemental Packs.

XenCenter also enables you to dismiss updates listed on the Updates tab. Dismissing an update hides the update entry from the list. Select any unwanted updates from the list and select Dismiss and then Dismiss Selected. To dismiss all the updates, select Dismiss All. If you would like to see updates which were previously dismissed, select Restore Dismissed Updates.

Authenticating your XenCenter to receive updates

To provide a more secure service for hotfix downloads, XenCenter now requires that you authenticate it with Citrix to automatically download and apply hotfixes.

Citrix Hypervisor updates are hosted on the Citrix Support site. The support site restricts the download of these updates to customers with a Citrix account. Some downloads are restricted to customers who have an active Citrix Success Services (CSS) agreement.


If your organization is an existing Citrix customer, ensure that your Citrix account meets the following requirements before using it to generate a client ID file:

  • You are registered as a contact for your organization.
  • Citrix Customer Service created your Citrix account as a web login associated with the registered contact.

To complete these steps, you can contact Citrix Customer Service.

To be able to download the hotfixes that are restricted to CSS customers, your organization must have an active Citrix Success Services agreement.


If you are unsure whether your Citrix account can be used to download CSS-only hotfixes through XenCenter, log in to https://support.citrix.com and check that you can download a CSS-only hotfix file through the browser.

Importing a client ID JSON file

To receive updates to Citrix Hypervisor through XenCenter, you must request a client ID JSON file from Citrix and import this file into your XenCenter instance. This setup task is required only once for each user of an instance of XenCenter.

  1. In the XenCenter menu, go to Tools > Options. The Options window opens.
  2. In the Updates tab, go to the Client ID section.
  3. Click the provided link to go to the page Generate and Download a Client ID in your web browser.
  4. You are prompted to log in to your Citrix account. If your organization has an active Citrix Success Services agreement, ensure that you use a Citrix account that is associated with this organization.


    Creating a user account using the Need an Account on this login screen does not associate your new user account with any existing organization and its associated Citrix Success Services entitlements.

  5. After you log in, click the Download Client ID button. The client ID is provided as a JSON file (xencenter_client_id.json).
  6. Return to XenCenter.
  7. In the Location field, browse to the location of the JSON file you downloaded (xencenter_client_id.json) and select the file.
  8. Click OK.

If you do not complete these steps in advance, XenCenter prompts you to obtain and install a client ID file when you first use it to install an update.

About the client ID

  • The client ID is unique to your Citrix account.
  • The client ID does not expire.
  • The client ID is not affected by a password change or password expiry in your Citrix account.
  • The client ID is not revoked by changes to Citrix account privileges.

Before you update

Before you apply an update to your servers, pay careful attention to the following:

  1. Citrix strongly recommends that you read the release notes published with each update.
  2. Back up your data before applying an update, just as you would with any other maintenance operations. For backup procedures, see Disaster recovery and backup.
  3. We recommend that you reboot all your servers before installing an update and then verify their configuration. For example, check that the VMs start and that storage is accessible. This recommendation is because some configuration changes take effect only after a server is rebooted. The reboot might uncover configuration problems that might cause the update to fail.
  4. When you are upgrading a pool of servers to a newer version, you must upgrade each server in a pool starting with the pool master. Ensure that the pool is up and running before applying any updates.
  5. Update ALL servers in a pool within a short period: running a mixed-mode pool (a pool that includes updated and non-updated servers) is not a supported configuration. Schedule the updates to minimize the amount of time that a pool runs in a mixed state.
  6. Update all servers within a pool sequentially, always starting with the pool master.
  7. After applying an update to all servers in a pool, update any required driver disks before rebooting the servers.

Viewing available updates

The Updates section of the Notifications view lists the updates that are available for all connected servers and pools.


  • By default, XenCenter periodically checks for Citrix Hypervisor and XenCenter updates. Select Refresh to manually check for available updates.
  • If the Updates tab cannot find any updates because you have disabled automatic check for updates, a message appears on the Updates tab. Select Check for Updates Now to manually check for updates.

You can select from the View menu whether to view the list of updates By Update or By Server.

When you view the list of updates by update, XenCenter displays the list of updates. You can order these updates by Server / Pool or by Date.

  • Cumulative Updates and new releases are displayed at the top of this list. Not all new releases can be applied as an update.
  • To export this information as a .csv file, select Export All. The .csv file lists the following information:

    • The update name
    • A description of the update
    • The servers that this update can be applied to
    • The timestamp of the update
    • A reference to the webpage that the update is downloaded from
  • To apply an update to a server, from the Actions menu for that update select Download and Install. This action extracts the update and opens the Install Update wizard on the Select Servers page with the relevant servers selected. For more information, see the following section Updating a Pool Automatically.
  • To open the release note of an update in your browser, select the Actions menu and select Go to Web Page.

When you view the list of updates by server, XenCenter displays the list of servers connected to XenCenter. This list shows both the updates that can be applied to the servers and the updates that are installed on the servers.

  • To export this information as a .csv file, select Export All. The .csv file lists the following information:

    • The Pool that the server belongs to
    • The Server name
    • The Status of the installed Citrix Hypervisor
    • The update Status of the server
    • The Required Updates for this server
    • The Installed Updates for this server
  • To apply the updates, select Install Updates. This action opens the Install Update wizard on the Select Update page. For more information, see the following section Updating a Pool Automatically.

Updating a pool automatically

XenCenter allows you to apply automated updates that are needed to bring your servers up-to-date. You can apply these updates to one or more pools.

When you choose to apply automated updates, XenCenter applies the minimum set of updates that are required to bring the selected pool or the standalone server up-to-date. When a cumulative update is available for the currently applied release, XenCenter applies the new cumulative update baseline and all available hotfixes for that cumulative update. If you do not want to update to the cumulative update baseline, instead manually download the hotfixes available for the currently applied release and apply them to your servers.

XenCenter minimizes the number of reboots required to bring the pool or the standalone server up-to-date, and where possible, limits it to a single reboot at the end. For more information, see Applying Automated Updates.

Applying an update to your managed servers

The update installation mechanism in XenCenter allows you to download and extract the selected update. This mechanism also enables you to apply an update to multiple servers and pools using the Install Update wizard. During the process, the Install Update wizard automatically performs these steps:

  1. It migrates VMs off each server
  2. It places the server in Maintenance mode
  3. It applies the update
  4. It reboots the server if necessary
  5. It migrates the VMs back to the updated server

Any actions that were taken at the pre-check stage to enable the updates to be applied, such as turning off high availability, are reverted.

When you install a Current Release, the Install Update mechanism offers to apply the minimum set of hotfixes on the new version to bring the servers up-to-date.

The following section provides step-by-step instructions on extracting and applying an update using the Install Update wizard. If you are planning to apply an update that you have already downloaded from the Citrix Support website, see Installing previously downloaded updates.

  1. From the XenCenter menu, select Tools and then Install Update.
  2. Review the information on the Before You Start page and select Next to continue.
  3. Select the updates to install and select Next to continue.
  4. Select the servers to install updates on and select Next to continue.


    • If you are installing a current release, XenCenter also offers to apply the minimum set of updates (hotfixes) after installing the current release.
    • If you are installing an update (hotfix), XenCenter downloads and extracts the update, and uploads it to the servers you have specified. The Upload page displays the status of the upload.

The Install Update wizard performs various prechecks to verify that the update can be applied on the selected servers and displays the result. The wizard also checks whether the servers need to be rebooted after the update is applied and displays the result. In addition, the Install Update wizard checks whether a live patch is available for the update and whether the live patch can be successfully applied to the servers. For information about Live Patching, see Live Patching in Citrix Hypervisor.

Follow the on-screen recommendations to resolve any update prechecks that have failed. If you prefer XenCenter to automatically resolve all failed prechecks, select Resolve All. When the prechecks have been resolved, select Next to continue.

If you are installing a current release, XenCenter downloads the updates, uploads them to the default SR of the pool, and installs the updates. The Upload and Install page displays the progress.


  • If the default SR in a pool is not shared, or does not have enough space, XenCenter uploads the update to another shared SR with sufficient space. If none of the shared SRs have sufficient space, the update is uploaded to local storage of the pool master.
  • If the update process cannot complete for any reason, XenCenter halts the process. This halt allows you to fix the issue and resume the update process by clicking the Retry button.

See Step 10 to complete the current release installation process.

If you are installing an update (hotfix), choose an Update Mode. Review the information displayed on the screen and select an update mode. If the update contains a live patch that can be successfully applied to the servers, it displays No action required on the Update Mode page.


If you select Cancel at this stage, the Install Update wizard reverts the changes and removes the update file from the server.

Select Install update to proceed with the installation. The Install Update wizard shows the progress of the update, displaying the major operations that XenCenter performs while updating each server in the pool.

Select Finish to close the Install Update wizard. If you chose to carry out the post-update tasks, do so now.

Installing previously downloaded updates

XenCenter enables you to install updates that you have already downloaded. Update files are delivered as zip files on the Citrix Support website.

  1. From the XenCenter menu, select Tools and then Install Update.
  2. Read the information displayed on the Before You Start page and then select Next.
  3. On the Select Update page, select Browse to locate the update file and then select Open. Select Next to continue.
  4. Select the pool and servers that you would like to update. Any servers or pools that cannot be updated are grayed out. Select Next to continue.
  5. Follow the instructions on the Install Update wizard to complete the update installation process.
  6. Select Finish to exit the wizard.
Updating Managed Servers