An instant-clone desktop pool is an automated desktop pool created from a golden image using the vmFork technology (called instant clone API) in vCenter Server.

Instant clone technology replaces View Composer linked clone as the process for creating non-persistent desktops in Horizon. In addition to using the instant clone API from vCenter Server, Horizon also creates several types of internal VMs (Internal Template, Replica VM, and Parent VM) to manage these clones in a more scalable way.

Instant clones share the virtual disk of the parent VM and consume less storage than full VMs. In addition, instant clones share the memory of the parent VM when they are first created, which contributes to fast provisioning. As users log into these cloned desktops, additional memory is consumed.

While the use of a parentVM is helpful in improving the provisioning speed, it does increase the memory requirement across the cluster. In some cases when the benefit of having more memory outweighs the increase in provisioning speed, Horizon automatically chooses to provision instant clones directly from a replicaVM without creating any parentVM. This feature is called Smart Provisioning. A single instant clone pool can have instant clones that are created with or without parentVMs.

An instant-clone desktop pool has the following benefits:

  • The provisioning of instant clones is fast.
  • Instant clones are always created in a powered-on state, ready for users to connect to. Guest customization and joining the Active Directory domain are completed as part of the initial power-on workflow.
  • You can patch a pool of instant clones in a rolling process with zero downtime.