An instant-clone desktop pool is an automated desktop pool. vCenter Server creates the desktop VMs based on the settings that you specify when you create the pool.
Similar to View Composer linked clones, an instant-clone desktop pool is based on a parent VM in vCenter Server, known as the master image. For instant-clone desktops, a parent VM is an internal VM that Horizon 7 creates and maintains, which is based on the master image. You cannot modify this internal parent VM. However, you can make changes to the master image.
Instant clones share a virtual disk of the master image and therefore consume less storage than full VMs. In addition, instant clones share the memory of the master image. Instant clones are created using the vmFork technology. An instant-clone desktop pool has the following key characteristics:
The provisioning of instant clones is faster than View Composer linked clones.
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.
For dedicated instant-clone desktop pools, users are assigned a particular remote desktop and return to the same desktop at each login. When a user logs out, a resync operation on the master image retains the VM name and the Mac IP address of the VM after logoff.
For floating instant-clone desktop pools, users are assigned random desktops from the pool. When a user logs out, the desktop VM is deleted. New clones are created according to the provisioning policy, which can be on-demand or up-front.
With the push-image operation, you can re-create the pool from any snapshot of any master image. You can use a push image to roll out operating system and application patches.
When clones are created, Horizon 7 selects a datastore to achieve the best distribution of the clones across the datastores. No manual rebalancing is necessary.
View storage accelerator is automatically enabled.
Transparent page sharing is automatically enabled.
Instant clones require static port binding with the elastic port allocation. Do not change the port binding to ephemeral. If you get an error message with static port binding, see the VMware Knowledge Base (KB) article http://kb.vmware.com/kb/2150925.
Instant clones and Storage vMotion are compatible. When you create an instant-clone desktop pool on a Storage DRS datastore, the Storage DRS cluster does not appear in the list in the desktop pool creation wizard. However, you can select individual Storage DRS datastores.
In Horizon 7 version 7.0.3 or later, internal validation checks determine if the instant clone and internal template have valid IP addresses and a network connection. If a virtual machine has a NIC that cannot be assigned an IP address during provisioning, instant-clone provisioning fails.
You can add a Virtual Trusted Platform Module (vTPM) device to instant clone desktop pools.
To set up the Key Management Server cluster, which is a prerequisite, see Set up the Key Management Server Cluster in the vSphere Security document.
For compatibility requirements, see Securing Virtual Machines with Virtual Trusted Platform Module in the vSphere Security document.
The master image used for vTPM Instant Clone pools must have VBS enabled when creating the VM, as well as the local security policy set to enable VBS inside the guest.
You can also select or deselect the option to add or remove a vTPM during a push-image operation.
You can vMotion instant clones that are configured with NVIDIA GRID vGPU without any impact to vGPU functionality.
Because Horizon 7 can create instant clones quickly, you do not need to provision desktops up front or have many ready desktops. Compared with View Composer linked clones, instant clones can make the task of managing large desktop pools easier and also reduce the amount of hardware resources that is required.
Instant clones have the following compatibility requirements:
vSphere 6.0 Update 1 or later.
Virtual machine hardware version 11 or later.
As a best practice, configure distributed virtual switches in the vSphere environment. It is mandatory to configure distributed virtual switches in the vSphere environment for dedicated instant clones.
Instant clones have the following multi-LAN compatibility requirements:
vSphere 2016 and above.
ESXi 6.0 U1 or newer.
Virtual distributed switch only. There is no support for the standard switch.
Port group must be static port binding with a fixed port allocation. There is no support for dynamic ports or ephemeral ports.
No dependency on guest operating systems.
Supports only IPv4 settings.
In Horizon 7, instant clones have the following restrictions:
Instant-clone desktops cannot have persistent disks. Users can use network share or VMware App Volumes to store persistent user data. For more information about App Volumes, see https://www.vmware.com/products/appvolumes.
Virtual Volumes and VAAI (vStorage APIs for Array Integration) native NFS snapshots are not supported.
Sysprep and Quickprep are not available for desktop customization. Use ClonePrep, which is designed for instant clones.
Windows 8 or Windows 8.1 are not supported.
IPv6 is not supported.
Persona Management is not available.
You cannot specify a minimum number of ready (provisioned) machines during instant-clone maintenance operations. This feature is not needed because the high speed of creating instant clones means that some desktops are always available even during maintenance operations.
The disk space reclamation feature that is available to View Composer linked clones is not needed because instant clones are refreshed when users log out. For instant clones, reclaiming unused disk space in a VM does not have a significant impact on storage consumption.