Instant clones are a type of virtual machines that are created by cloning a running parent VM in memory, without requiring a full disk copy. This allows for faster provisioning and updating of RDS hosts in a farm. Instant clones can be patched in a rolling process with zero downtime by using the push-image operation, which replaces the existing instant clones with new ones that have the latest patches applied. The push-image operation can be performed on a per-farm basis or on multiple farms at once. The push-image operation preserves the user sessions and data on the existing instant clones until they are logged off or disconnected, and then deletes them. The new instant clones inherit the same settings and assignments as the old ones. Therefore, to deploy a RDS farm that can be patched in a rolling process with zero downtime, the administrator should create an instant-clone RDS desktop farm.Reference:Instant Clones for RDSH in VMware Horizon 7.1and [VMware Horizon 8.x Professional Course]