Product Documentation

vDisks

Citrix XenDesktop with personal vDisk technology is a high-performance enterprise desktop virtualization solution that makes VDI accessible to workers who require personalized desktops, by using pooled-static virtual machines.

Provisioning Services target devices that use personal vDisks are created using the Citrix XenDesktop Setup Wizard. Within a Provisioning Services farm, the wizard creates target devices, adds target devices to an existing site’s collection, and then assigns an existing vDisk, which is in standard image mode, to that device.

The wizard also creates XenDesktop virtual machines to associate with each Provisioning Services target device. A catalog exists in Citrix Desktop Studio that allows you to preserve the assignment of users to desktops; the same users are assigned the same desktop for later sessions. In addition, a dedicated storage disk is created (before logon) for each user so they can store all personalization’s to that desktop (personal vDisk). Personalizations include any changes to the vDisk image or desktop that are not made as a result of an image update, such as application settings, adds, deletes, modifications, or documents. Target devices using personal vDisks can also be reassigned a different vDisk if that vDisk is from the same base vDisk lineage. For additional information on using personal vDisks with XenDesktop, refer to XenDesktop’s About Personal vDisks topic.

Inventory is run when a Provisioning Services vDisk is configured or updated. The method selected to configure or update a vDisk image for use as a personal vDisk image may determine when vDisk inventory runs in your deployment. The content that follows identifies the different methods from which you can choose, provides the high-level tasks associated with each method, and indicates at which point inventory runs for each method.

After configuring and adding a new personal vDisk image, do not use your golden VM as the machine template because it creates an unnecessary large disk as your write cache disk (the size of your original HDD).

Configure and deploy a new personal vDisk image

Configuration methods include:

  • Configure in the following order: Provisioning Services, then capture the image, then XenDesktop
  • Configure in the following order: Provisioning Services, then XenDesktop, then capture the image
  • Configure in the following order: XenDesktop, then Provisioning Services, then capture the image
  • Configure using Machine Creation Services (MCS)

Provisioning Services, then capture image, then XenDesktop

  1. Install and configure the OS on a VM.
  2. Install the Provisioning Services target device software on the VM.
  3. Run the Provisioning Services Imaging Wizard to configure the vDisk.
  4. Reboot.
  5. The Provisioning Services Image Wizard’s second stage runs to capture the personal vDisk image.
  6. From the Console, set the target device to boot from the vDisk.
  7. Configure the VM to boot from the network, then reboot.
  8. Install XenDesktop software on the VM, then configure with advanced options for personal vDisk.
  9. Manually run inventory, then shut the VM down.
  10. From the Console, place the vDisk in Standard Image Mode. Image is ready for deployment.

Provisioning Services, then XenDesktop, then capture image

  1. Install and configure the OS in a VM.
  2. Install the Provisioning Services target device software on the VM.
  3. Install XenDesktop software and configure with advanced options for personal vDisks enabled.
  4. Reboot.
  5. Log on to the VM.
  6. Run the Provisioning Services Imaging Wizard on the VM to configure the vDisk. (Inventory automatically runs after the VM successfully shuts down and reboots.)
  7. The Imaging Wizard’s second stage runs to capture the personal vDisk image.
  8. Shut the VM down.
  9. From the Console, place the personal vDisk image in Standard Image Mode. The personal vDisk is ready for deployment.
  10. Before using a VM template to provisioning multiple VMs to a XenDesktop site, verify the new vDisk can successfully boot from the VM created to serve as the machine template (not the golden VM), and verify the write cache disk is recognized successfully:

    a. Place the vDisk image in Private Image mode.

    b. Boot the new vDisk image from the VM.

    c. Format the new write cache partition manually.

    d. Shut down the VM. During the shut down process, when prompted run personal vDisk inventory.

    e. Turn this VM into a template.

XenDesktop, then Provisioning Services, then capture image

  1. Install and configure the OS in a VM.
  2. Install XenDesktop software on the VM, then configure with advanced options for personal vDisk enabled.
  3. Reboot.
  4. Log on to, then shutdown the VM. Inventory automatically runs at shutdown.
  5. Log on to, then install the Provisioning Service’s target device software.
  6. Run the Provisioning Services Imaging Wizard on the VM to configure the vDisk.
  7. Reboot. (Inventory automatically runs after the VM successfully shuts down and reboots.)
  8. The Imaging Wizard’s second stage runs to capture the personal vDisk image.
  9. Shut the VM down.
  10. Place the vDisk in Standard Image Mode. The personal vDisk is ready for deployment.
  11. Before using a VM template to provisioning multiple VMs to a XenDesktop site, verify the new vDisk can successfully boot from the VM created to serve as the machine template (not the golden VM), and verify the write cache disk is recognized successfully:

    a. Place the vDisk image in Private Image mode.

    b. Boot the new vDisk image from the VM.

    c. Format the new write cache partition manually.

    d. Shut down the VM. During the shut down process, when prompted run personal vDisk inventory

    e. Turn this VM into a template.

To configure MCS

  1. Install and configure the OS in a MCS VM.
  2. Install XenDesktop software and configure with advanced options for personal vDisks.
  3. Reboot the VM.
  4. Log onto the VM, and then shut the VM down. Inventory automatically runs at shutdown.
  5. The personal vDisk image is ready for deployment.

Update an existing personal vDisk image

Updating existing personal vDisk methods include using:

  • Provisioning Services
  • MCS

Updates for both Provisioning Services and MCS must be done on VMs that do not have a personal vDisk.

Provisioning Services

  1. Create a new version of the vDisk image.
  2. Boot the VM from the vDisk image in Maintenance Mode.
  3. Install updates on the new vDisk version.
  4. Shut the VM down. Inventory runs automatically when the VM shuts down.
  5. Promote the new version to either Test or Production. Other VMs will have access to the updated vDisk version the next time they reboot.

MCS

  1. Boot the ‘golden’ VM.
  2. Install updates on the VM.
  3. Shut the VM down. Inventory automatically runs when the VM is shutdown.

For additional information on how to create a Provisioning Services target device that uses a personal vDisk, refer to Deploy virtual desktops to VMs using the XenDesktop Setup Wizard. To view the properties of a Provisioning Services target device configured to use a personal vDisk, refer to Configure target devices that use personal vDisks.

Creating a machine catalog with on-premises PVS servers

From the Cloud DDC you can create a machine catalog and choose to deploy machines using PVS and point it at a PVS Collection. The machines within this collection must all have AD accounts associated with them. The PVS PowerShell snapin that the cloud DDC uses first gets the Device records from the PVS database and looks up the domain SIDs in those device records. If the device record does not contain a domain SID, then the snapin tries to talk to AD directly and fails because that domain does not exist in the cloud.

Using the Console to view vDisk properties

In the Console, the vDisk Properties dialogs allows you to modify vDisk configuration settings. To view an existing vDisk’s properties, choose one of the following methods:

  • Highlight a vDisk in the Console, then select Properties from the Action menu.
  • Right-click on the vDisk in the Console, then select Properties.
  • Double-click on the vDisk in the Console’s details pane.

    Image of the console details pane

General tab

The following list describes each menu option on the General tab:

  • Site: The name of the site where this vDisk is a member of its vDisk Pool. This property can not be modified in this dialog.
  • Store: The name of the store where the vDisk resides. This property can not be modified in this dialog.
  • Filename: The filename that was given to this vDisk when it was created. This property can not be modified in this dialog.
  • Size: The file size of this vDisk.
  • Access mode: Access mode options.
  • Select the vDisk access mode:
    • Standard Image (multi-device, read only access with write cache options)
    • Private Image for use with a single target device, which has read and write access.
    • Local Hard Disk Drive (read/write)
  • Select the cache type: For Standard Image only, select the write cache type:
    • Cache on the device hard drive (NTFS file format)
    • Cache on device hard drive persisted (experimental stage only)
    • Cache in device RAM
    • Cache on device RAM with overflow on hard disk
    • Cache on server
    • Cache on server persisted
  • Select the cache size (MBs): If you select Standard Image and Cache in target device RAM, select the cache size in megabytes. Default is 4096. For 32-bit systems, the max size of the RAM write cache is determined by the registry setting WcMaxRamCacheMB in the BNIStack Parameters. This is a DWORD parameter. The default value used is 3584 MB.
  • BIOS menu text: This field is optional and allows you to enter a menu text that will display on the target device when that device starts. The user can then select which vDisk to boot from.

    Important:

    If vDisks with the same name from different Stores are assigned to the same target device, they display as duplicate names in the menu unless different menu text or descriptions are provided.

  • Enable Active Directory machine account password management: Enables the Active Directory password management features. If your target devices belong to a domain and share a vDisk, also refer to the Active Directory section on the Options tab of the Provisioning Server Properties dialog.
  • Enable printer management: Enables the printer management option if you are not using a different printer system that installs valid printers on each target device. To view printer details for an individual target device, refer to the Target Device Properties vDisk tab, then click the Printers button.
  • Enable streaming of this vDisk: Enables this vDisk to be streamed to target devices.

Identification tab

The following list describes each menu option on the Identification tab:

  • Description: Provides a description for this vDisk.
  • Date: For informational use only. Initially set to a string representing the creation date of the image file.
  • Author: For informational use only. Set as appropriate for your installation.
  • Title: For informational use only. Set as appropriate for your installation.
  • Company: For informational use only. Set as appropriate for your installation.
  • Internal name: For informational use only. Set as appropriate for your installation.
  • Original file: For informational use only. Set as appropriate for your installation.
  • Hardware target: For informational use only. Set as appropriate for your installation.

Microsoft volume licensing tab for vDisk file

The following menu option appears on the Microsoft volume licensing tab:

Note:

The vDisk license mode must be set before target devices can be activated.

  • Microsoft volume licensing: If using Microsoft KMS or MAK volume licenses for target devices using this vDisk image, select that licensing option from those listed below. Otherwise, select None:
    • None
    • Key Management Service (KMS)
    • Multiple Activation Key (MAK)

    Note:

    In order for MAK licensing to work, the Volume Activation Management Tool (VAMT) must be installed on all login servers within the farm. This tool is available from Microsoft.

Auto update tab

The following list describes each menu option on the Auto update tab:

Note:

This vDisk update method can only be used on a base disk that has no VHDX versions associated with it.

  • Enable automatic updates for this vDisk: Enables the Automatic Disk Update process on this vDisk file.
  • Class: Enter a class to associate to the vDisk file. This field is used with Automatic Disk Update and the Managed Disk Feature in order to match new vDisk file to the appropriate target devices. Up to 40 characters can be entered.
  • Type: Enter a type to associate with the vDisk file. This field is used in Automatic Disk Update, in order to match the new vDisk file to the old file. Up to 40 characters can be entered.
  • Major #, Minor #, Build #: If the new vDisk version is greater than the old image version, the vDisk image is replaced for matching Class and Type images. Precedence is: Major, then Minor, then Build.

    Note:

    During the update process, if several vDisks exist with the same version number because the version number was not incremented, Provisioning Services uses the first updated vDisk presented in the list.

  • Serial #: Initially set to a random Globally Unique Identifier (GUID).The user can set the serial number as needed. The serial number is used to ensure that a delta file is applied to the correct vDisk image file.

Configuring the vDisk access mode

Use the Console to select from the following vDisk access modes:

  • Standard Image: Select this mode if a vDisk is shared by multiple target devices (write-cache options enabled).
  • Private Image: Select this mode if a vDisk is only used by a single target device (read/write access is enabled).

Standard Image mode

Standard Image mode allows multiple target devices to stream from a single vDisk image at the same time. This reduces the amount of vDisk management and reduces storage requirements.

When a vDisk is configured to use Standard Image mode, it is set to read-only mode. Each target device then builds a write cache to store any writes the operating system needs to make. There are several write-cache options available. Because the vDisk is read-only, each time a target device boots, it always boots from a ‘clean’ vDisk. If a machine becomes infected with a virus or spyware, the target device only needs to reboot the image.

When updates are made to a vDisk in Standard Image mode, changes against the base vDisk image are captured in a differencing disk file (.avhdx), resulting in a new version of the base image. Each new version remains directly associated with the base image. Versioning allows for the updates captured in the differencing disk to be staged (Maintenance, Test, Production) before those changes become available to Production devices. If issues are encountered with a version, that version can simply be reverted. For details on versioning, refer to Updating vDisks.

Although each target device uses the same vDisk, Provisioning Services personalizes the streamed image for each target device, providing the information needed to ensure the device is uniquely identifiable on the network. You can also specify additional personality settings for each device: you can store application-specific values in the database and retrieve the target device’s unique value as the device loads. For more details, refer to Managing Target Device.

Private Image mode

A vDisk that is in Private Image mode closely models how a computer uses a regular hard drive. That is, only one target device can use a Private Image vDisk at a time.

The following illustrates Private Image vDisks (read/write) that are each assigned to a single production device, and a Standard Image vDisk (read-only) that is assigned to and shared by a collection of production devices. For Standard Image vDisks, write cache options include cache on server disk, on a device’s hard disk drive, or in the device’s RAM.

Image of Private Image vDisks (read/write)

To configure the vDisk mode and any applicable write cache destination

Note:

Only write cache destinations that are supported for Standard access mode appear enabled.

  1. On the Console, right-click on the vDisk for which you want to configure the vDisk access mode, then select vDisk Properties. The vDisk Properties dialog appears.
  2. Click on the General tab, then select the image mode (Standard or Private) that applies to this vDisk from the Access Mode drop-down list.
  3. If Standard image was selected, from the cache destination drop-down list, select the appropriate write cache destination.
  4. Click OK to exit the vDisk Properties dialog.