The architecture that this guide describes is based on VMware Horizon 8, which provides a complete end-to-end solution delivering Microsoft Windows virtual desktops to users on a wide variety of endpoint devices. Virtual desktops are dynamically assembled on demand, providing users with clean, yet personalized, desktops each time they log in.
VMware Horizon 8 provides a complete virtual desktop delivery system by integrating several distributed components with advanced configuration tools that simplify the creation and real-time management of the virtual desktop infrastructure.
The core Horizon components include:
- Horizon Connection Server (HCS)—Installed on servers in the data center. The HCS brokers client connections, authenticates users, entitles users by mapping them to desktops and/or pools, establishes secure connections from clients to desktops, supports single sign-on, and sets and applies policies.
- Horizon Administrator—Provides administrator functions such as deployment and management of Horizon desktops and pools, setting and controlling user authentication, and more.
- Horizon Agent—Installed on all VMs, physical machines, and Terminal Service servers that are used as a source for Horizon desktops. On VMs, the agent is used to communicate with the Horizon client to provide services such as USB redirection, printer support, and more.
- Horizon Client—Installed on endpoints for creating connections to Horizon desktops that can be run from tablets, Windows, Linux, or Mac desktops or laptops, thin clients, and other devices.
- Unified Access Gateway—Provides a way to securely deliver connections that require a higher level of security to access, such as remote connections from the Internet.
- Horizon Portal—Provides access to links for downloading full Horizon clients. Enable the HTML access feature to run a Horizon desktop inside a supported browser.
- vCenter Server—Provides centralized management and configuration to the entire virtual desktop and host infrastructure. It facilitates configuration, provisioning, and management services.
Horizon clone technology
VMware Horizon 8 offers the following methods for cloning desktops:
- Full clones—Full clones are typically used in environments where dedicated resources are assigned to specific users. Full clones are typically not ideal for large-scale VDI deployments because full copies have no connection to the original VM. Updates must be performed on each VM with this approach. Additionally, full clones are not space-efficient as they will duplicate much of the same data to all of the VMs. Space efficiency technologies may be enabled at the storage layers, but that may incur additional CPU overhead and reduce VM and user density per node as well as overall performance.
- Instant clones—As of Horizon 8, instant clones are available with all licensing levels. These clones include enhancements and new capabilities such as “Smart Provisioning” to help reduce storage requirements and costs. This technology can provision a VM the instant that a user requests one. The result is a far easier approach to operating system updates and patch management, because the VM is created close to the login time. You can use the combination of Just-in-Time Management Platform (JMP) features such as App Volumes and Dynamic Environment Manager to emulate persistence. For more information on instant clones, see the VMware Horizon 7 Instant-Clone Desktops and RDSH Servers White Paper.
- Linked clones—Linked clones require fewer storage resources than full clones. This technology is appropriate for many VDI use cases. Differences between the parent VM and the clone are maintained in a delta file. While updates can be rolled out effectively, multiple VM rebuilds are required to correctly deploy a patch at the operating system level. Operating system updates are rolled out to the parent images, and then the Desktop pool is pointed to the new snapshot with the updates. A Horizon Composer instance is required with linked clones to manage the recompose functions of the pool.
Note: Linked clones are being deprecated in Horizon 8.0 and will not be available in future versions of VMware Horizon.