Core components of VMware View
This book assumes a familiarity with server virtualization, more specifically, VMware vSphere (sometimes referred to as ESX by industry graybeards). Therefore, this article will focus on:
- The VMware vCenter Server
- The types of View Connection Server
- Agent and client software
VMware vCenter is a required component of a VMware View solution. This is because the View Connection Server interacts with the underlying Virtual Infrastructure (VI) through vCenter Web Service (typically over port 443). vCenter is also responsible for the complementary components of a VMware View solution provided by the underlying VMware vSphere, including VMotion and DRS (used to balance the virtual desktop load on the physical hosts). When an end customer purchases VMware View bundles, VMware vCenter is automatically included and does not need to be purchased via a separate Stock Keeping Unit (SKU). In the environments leveraging vSphere for server virtualization, vCenter Server is likely to already exist. To ensure a level set on the capabilities that VMware vCenter Server provides, the key terminologies are listed as follows:
- vMotion: It is the ability to live migrate a running virtual machine from one physical server to another with no downtime.
- DRS: It is the vCenter Server capability that balances virtual machines across physical servers participating in the same vCenter Server cluster.
- Cluster: It is a collection of physical servers that have access to the same networks and shared storage. The physical servers participating in a vCenter cluster have their resources (for example, CPU, memory, and so on) logically pooled for virtual machine consumption.
- HA: It is the vCenter Server capability that protects against the failure of a physical server. HA will power up virtual machines that reside on the failed physical server on available physical servers in the same cluster.
- Folder: It is a logical grouping of virtual machines, displayed within the vSphere Client.
- vSphere Client: It is the client-side software used to connect to vCenter Servers (or physical servers running vSphere) for management, monitoring, configuration, and other related tasks.
- Resource pool: It is a logical pool of resources (for example, CPU, memory, and so on). The virtual machines (or the groups of virtual machines) residing in the same resource pool will share a predetermined amount of resources.
Designing a VMware View solution often touches on typical server virtualization design concepts such as the proper cluster design. Owing to this overlap in design concepts between server virtualization and VDI, many server virtualization engineers apply exactly the same principles from one solution to the other.
The first misstep that a VDI architect can take is that VDI is not server virtualization and should not be treated as such. Server virtualization is the virtualization of server operating systems. While it is true that VDI does use some server virtualization (for the connection infrastructure, for example), there are many concepts that are new and critical to understand for success.
The second misstep a VDI architect can make is in understanding the pure scale of some VDI solutions. For the average server virtualization administrator with no VDI in their environment, he/she may be tasked with managing a dozen physical servers with a few hundred virtual machines. The authors of this book have been involved in VDI solutions involving tens of thousands of vDesktops, well beyond the limits of a traditional VMware vSphere design.
VDI is often performed on a different scale. The concepts of architectural scaling are covered later in this book, but many of the scaling concepts revolve around the limits of VMware vCenter Server. It should be noted that VMware vCenter Server was originally designed to be the central management point for the enterprise server virtualization environments. While VMware continues to work on its ability to scale, designing around VMware vCenter server will be important.
So why do we need VMware vCenter in the first place, for the VDI architect?
VMware vCenter is the gateway for all virtual machine tasks in a VMware View solution. This includes the following tasks:
- The creation of virtual machine folders to organize vDesktops
- The creation of resource pools to segregate physical resources for different groups of vDesktops
- The creation of vDesktops
- The creation of snapshots
VMware vCenter is not used to broker the connection of an end device to a vDesktop. Therefore, an outage of VMware vCenter should not impact inbound connections to already-provisioned vDesktops as it will prevent additional vDesktops from being built, refreshed, or deleted.
Because of vCenter Server’s importance in a VDI solution, additional steps are often taken to ensure its availability even beyond the considerations made in a typical server virtualization solution.
Later in this book, there is a question asking whether an incumbent vCenter Server should be used for an organization’s VDI or whether a secondary vCenter Server infrastructure should be built.
View Connection Server
View Connection Server is the primary component of a VMware View solution; if VMware vCenter Server is the gateway for management communication to the virtual infrastructure and the underlying physical servers, the VMware View Connection Server is the gateway that end users pass through to connect to their vDesktop. In classic VDI terms, it is VMware’s broker that connects end users with workspaces (physical or virtual). View Connection Server is the central point of management for the VDI solution and is used to manage almost the entire solution infrastructure. However, there will be times when the architect will need to make considerations to vCenter cluster configurations, as discussed later in this book. In addition, there may be times when the VMware View administrator will need access to the vCenter Server.
The types of VMware View Connection Servers
There are several options available when installing the VMware View Connection Server. Therefore, it is important to understand the different types of View Connection Servers and the role they play in a given VDI solution.
Following are the three configurations in which View Connection Server can be installed:
- Full: This option installs all the components of View Connection Server, including a fresh Lightweight Directory Access Protocol (LDAP) instance.
- Security: This option installs only the necessary components for the View Connection portal. View Security Servers do not need to belong to an Active Directory domain (unlike the View Connection Server) as they do not access any authentication components (for example, Active Directory).
- Replica: This option creates a replica of an existing View Connection Server instance for load balancing or high availability purposes. The authentication/ LDAP configuration is copied from the existing View Connection Server.
Our goal is to design the solutions that are highly available for our end customers. Therefore, all the designs will leverage two or more View Connection Servers (for example, one Full and one Replica).
The following services are installed during a Full installation of View Connection Server:
- VMware View Connection Server
- VMware View Framework Component
- VMware View Message Bus Component
- VMware View Script Host
- VMware View Security Gateway Component
- VMware View Web Component
- VMware VDMDS
VMware VDMDS provides the LDAP directory services.
View Agent is a component that is installed on the target desktop, whether physical (seldom) or virtual (almost always). View Agent allows the View Connection Server to establish a connection to the desktop. View Agent also provides the following capabilities:
- USB redirection: It is defined as making a USB device—that is connected locally—appear to be connected to vDesktop
- Single Sign-On (SSO): It is done by using intelligent credential handling, which requires only one secured and successful authentication login request, as opposed to logging in multiple times (for example, at the connection server, vDesktop, and so on)
- Virtual printing via ThinPrint technology: It is the ability to streamline printer driver management through the use of ThinPrint (OEM)
- PCoIP connectivity: It is the purpose-built VDI protocol made by Teradici and used by VMware in their VMware View solution
- Persona management: It is the ability to manage a user profile across an entire desktop landscape; the technology comes via the recovery time objective (RTO) acquisition by VMware
- View Composer support: It is the ability to use linked clones and thin provisioning to drastically reduce operational efforts in managing a mid-to-large-scale VMware View environment
View Client is a component that is installed on the end device (for example, the user’s laptop). View Client allows the device to connect to a View Connection Server, which then directs the device to an available desktop resource. Following are the two types of View Clients:
- View Client
- View Client with Local Mode
These separate versions have their own unique installation bits (only one may be installed at a time). View Client provides all of the functionality needed for an online and connected worker. If Local Mode will be leveraged in the solution, View Client with Local Mode should be installed.
VMware View Local Mode is the ability to securely check out a vDesktop to a local device for use in disconnected scenarios (for example, in the middle of the jungle).
There is roughly an 80 MB difference in the installed packages (View Client with Local Mode being larger). For most scenarios, 80 MB of disk space will not make or break the solution as even flash drives are well beyond an 80 MB threshold.
In addition to providing the functionality of being able to connect to a desktop, View Client talks to View Agent to perform the following tasks:
- USB redirection
- Single Sign-On