Fast provisioning saves time by using linked clones for virtual machine (VM) provisioning operations.

A linked clone is a duplicate of a VM that uses the same virtual disk as the original, with a chain of delta disks to track the differences between the original and the clone. If you deactivate fast provisioning, all provisioning operations result in full clones.

A linked clone cannot exist on a different vCenter Server data center or datastore than the original VM.

When you fast provision a VM, VMware Cloud Director creates a shadow virtual machine to support linked clone creation across vCenter Server data centers and datastores for the virtual machines that are associated with a specific vApp template.

A shadow VM is an exact copy of the original VM. VMware Cloud Director creates the shadow VM on the data center and datastore where the linked clone is created.

Important:

In-place consolidation of a fast-provisioned VM is not supported on storage containers that employ native snapshots. Datastores with enabled VMware vSphere Virtual Volumes and VMware vSphere Storage APIs Array Integration (VAAI) use native snapshots, so fast-provisioned VMs deployed to one of these storage containers cannot be consolidated. If you need to consolidate a fast-provisioned VM deployed to a VMware vSphere Virtual Volumes or VAAI-enabled datastore, you must relocate it to a different storage container.

You cannot add or remove Trusted Platform Module (TPM) devices from linked clones. VMware Cloud Director does not support vApp templates captured with the Replace option for TPM Provisioning. For more information on VMs with TPM devices, see Working with Virtual Machines.

View the Shadow Virtual Machines Associated With a vApp Template

Shadow virtual machines (VMs) support linked clones of VMs that are associated with vApp templates across vCenter Server data centers and datastores.

Shadow VMs are hidden full clones of templates which help with fast provisioning of VMs.

VMware Cloud Director creates shadow VMs in two ways:
  • When a shadow VM is missing on the datastore selected by the placement engine.
  • As a result of a periodic background job.
If activated, the periodic background job StorageProfileValidationJob runs every 24 hours and uses eager VM creation on each datastore for a given hub and storage policy pair. To activate the job for eager provisioning of shadow VMs, you must set the following property to true. 
valc.catalog.fastProvisioning=true
Note: The periodic background job creates shadow VMs on all datastores for all templates. The job increases the storage consumption even when you are not using the datastores or shadow VMs.

Procedure

  1. In the top navigation bar, click Libraries and in the left panel, select vApp Templates.
  2. Click the name of the vApp template that you want to explore.
  3. Select the Shadow VMs tab.