Product Documentation

Update a master image

May 07, 2013

To apply changes (for example, implement software updates) to all the desktops and applications from a machine catalog, update the master image. Managing the common aspects of users' desktops through a single master image lets you deploy system-wide changes, such as applying Windows updates or making configuration changes, to a large number of desktops very quickly. This lets you provide users with continuous access to their desktops so that they can continue working while any problems with the update are addressed.

Cloud deployments use templates in place of master images. Refer to the following information for preparing templates:

If the master image includes the latest VDA version, it enables the new VDA features.

Once you have prepared and tested a new or updated master image, modify the machine catalog to use the new master image. Desktops are updated with the new master image the next time users log off.

Note: After updating the master image, you must restart the machines through Studio for the changes to take effect and be available to your users. This may occur automatically; for example, when a user logs out of a random Desktop OS machine, or it may occur as part of a configured reboot schedule. Alternatively, you can restart a machine by finding and selecting it through Studio's Search node.

To update the master image

Before you update the master image, create a snapshot. Doing so lets you quickly revert a machine catalog to use the previous version of the master image should users encounter problems with updates.

Although Studio can create a snapshot, Citrix recommends that you create a snapshot using the Hypervisor Management console, and then select that snapshot in Studio. Using this method lets you provide a meaningful name and description rather than an automatically generated name.

Note the following

  • For GPU master images, you can change the master image only through XenServer's XenCenter console. See Prepare a master image for information about GPU master images.
  • For Provisioning Services (PVS) machine catalogs, you must publish a new vDisk to apply changes to the Provisioning Services machine catalogs. For detailed information, see Updating vDisks and Versioned vDisk Upgrade.
  1. In Studio, select the Machine Catalogs node, select a machine catalog in the results pane, and click Update Machine.
  2. On the Master Image page, select the host and the new or updated master image that you want to use.
    • For XenDesktop 7.x machine catalogs, a message prompts you to select a snapshot or virtual machine built using a 7.x VDA.
    • For machine catalogs running Windows XP or Windows Vista, an earlier VDA version is installed on Windows XP or Windows Vista machines.
  3. On the Rollout Strategy page, specify how the new or updated master image is applied to users' desktops and click Next.

    If you are deploying:

    Select:

    A non-urgent update and you want to minimize disruption to users

    On the next restart (not right now) to apply the update when users next log off.

    A non-urgent update and you want to inform users

    Notify users of the update and enter a message. Users see the specified message and the update is applied when they next log off.

    A critical update and you want to apply it to all users' desktops urgently

    Immediately (restart the machine now) to automatically log off users and restart their desktops.

    Select Distribution time in which you can restart all the machines at once or restart over designated time intervals such as 30 minutes, one hour, or two hours.

    A critical update and you want to apply it to all users' desktops urgently and you want to inform users

    Notify users of the update, and specify the time delay before applying the update. The timer starts when Studio finishes making a temporary copy of the new or updated master image in the appropriate location

    Enter a message that users see when they next log on, or if the specified time limit is reached, users are automatically logged off and their desktops restarted.

  4. On the Summary page, check that the details are correct and click Finish.

To revert to the previous version of the master image

A historical record of the master images for each machine catalog is stored in the Database. This lets you revert a machine catalog and use the previous version of the master image should users encounter problems with updates that you have made. Desktops revert to the previous master image the next time users log off.

If you delete, move, or rename any previous master images, including any snapshots in the chains leading to the master images, you cannot revert the machine catalog to use them. When Studio is unable to locate the previous master image, you can browse for an alternative master image from which to update the desktops.

  1. In the Studio, select the Machine Catalogs node, select your machine catalog in the results pane, and click Rollback machine update.
  2. On the Strategy page, specify how to apply the reverted master image to users' desktops.

    If reverting:

    Select:

    Users' desktops is not urgent and you want to minimize disruption to users

    None. Users' desktops are reverted when they next log off.

    Users' desktops is not urgent and you want to inform users

    Send message and enter a message. Users see the specified message and their desktops are reverted when they next log off.

    Users' desktops is critical and you want to revert all users' desktops urgently,

    Restart immediately to automatically log off users and restart their desktops.

    Users' desktops is urgent and you want to allow users some time to save their work before reverting their desktops

    Send message then restart after delay. Enter a message and specify the time delay before reverting the desktops. The timer starts when Studio finishes making a temporary copy of the reverted master image in the appropriate location. Users see the specified message and their desktops are reverted when they next log off or, if the specified time limit is reached, users are automatically logged off and their desktops restarted.

    The rollback strategy is only applied to desktops that need to be reverted. Users of desktops that have not been updated with the problematic master image that prompted the rollback, for example because the user has not logged off, do not receive any messages and are not forced to log off.

  3. On the Summary page, check that the details are correct and then click Finish.