In large, IT-intensive enterprises, the value of desktop and network computing (in the form of enhanced productivity and innovative capabilities) is unquestioned, but that doesn’t negate the difficulties of managing a huge, diverse fleet of PCs. The constant upgrades to PC hardware, applications, and operating systems make the governance and decision process more complex. For instance, how do IT executives know which upgrades are critical to user service and to stay competitive and which upgrades can be skipped or selectively applied?

With the current focus on global warming and Green IT, the question of PC deployment becomes even more challenging. Many users never turn off their PCs or monitors or apply the power-saving capabilities of their desktops, which complicates the drive towards IT sustainability. The bandwidth required to serve applications to all these PCs forces IT departments to buy more servers, network gear, and power and cooling equipment to support it. Security challenges, such as spyware, virus definitions, and firewall signature maintenance, add to the burden as well.

In an attempt to deal with the desktop computing model’s shortcomings, many manufacturers offer the thin client computing model. In this model, applications are deployed, managed, and supported at the server level, and the user attaches to the network with a specialized thin client device. These thin client devices are typically specially designed, sealed “black boxes,” containing only the firmware and I/O ports required to connect to the monitor, mouse, keyboard, and network. The boxes are designed to exchange only keystrokes, screen refreshes, and mouse clicks with the application residing on the server; the application runs on the server and feeds screen refreshes back to the thin client. For veterans of the mainframe era of computing, this model should be familiar, as it’s an update of the time-sharing concept common in the green screen days.

Benefits of thin client computing

The benefits of thin client computing are typically categorized in the following three areas:

  • Cost efficiency: According to a study by IDC, users of thin clients (when compared to full PC users) saw a decline in hardware and software costs of 40% and saw a reduction in IT operations costs by 29%. IDC found that annual hardware procurement costs dropped from $475 for a PC-based desktop to $285 per thin client, and operating expense for support and maintenance dropped from $498 per PC to $354 per client. IDC also found that IT worker productivity shot up by 56%, due to less trouble calls and hardware repairs required for thin clients vs. PCs.
    The Green IT benefits of the thin client model are: The tiny firmware boxes have no moving parts and draw significantly less power than a PC. In a study by Thin Client Computing, thin clients drew an average of 10 watts, while PCs drew an average of 69 watts. According to this study, an enterprise with 100 PCs could save $6,000 in electricity costs annually by migrating from PCs to thin clients.
  • Security: The thin client computing model is inherently more secure, since the applications and the computing power are all housed in the data center, with its strict rules and disciplines for change control and application installation and revision. With no disk access to install applications, transfer data, or introduce malware, thin clients are a perfect fit for many organizations’ strict security requirements.
  • Manageability: The migration to thin clients (which don’t require the constant patching, configuring, and updating of PCs) can significantly reduce support and maintenance requirements. When virus and malware protection and hardware maintenance are considered as well, the enhanced manageability of thin clients becomes undeniable.

As noted, the thin client computing model (which is sometimes referred to as server-based computing since the application and all resources are accessed from the server) resembles a modern version of the classic green screen time-sharing systems, which were popular in the mainframe days. Major manufacturers’ current thin client offerings are much advanced from the text-only, monochrome displays typical of mainframe systems and have evolved significantly from the early Citrix and Microsoft offerings (i.e., Citrix’s early MetaFrame server and Microsoft’s Terminal Server). Many thin clients now come with embedded Windows or Linux operating systems that allow them to display full desktop graphics and offer the familiar UI users expect. Manufacturers such as Hewlett-Packard (through its acquisition of thin-client veteran Neoware) offer thin clients in a laptop configuration that lacks hard drives and USB ports and uses wireless connections to access applications from the company network.

Virtualization has also swept the thin client market. By partitioning a single server into multiple virtual machines, IT teams can give thin client users the experience of a full PC, with their own virtual drives and device, in a virtual instance. Hewlett-Packard and NEC have partnered with VMware to offer specialized systems to help manage virtualized desktop environments based on thin clients. NEC’s Virtual PC Center is a virtualized server appliance with pre-configured VMware and a proprietary management system aimed at thin-client implementations.

Potential pitfalls of a thin client migration

Migrating to thin clients seems appealing based on the benefits outlined above, but there are risks and pitfalls to consider, which include the following:

  • No backup version: While a PC can have a backup version of the application installed locally so users can work in case of a network outage, thin clients don’t have this capability. When the network is down in a thin client environment, work comes to a screeching halt.
  • Network bandwidth and server capacity issues: While network bandwidth demands may be reduced because thin clients are sending only keystrokes, mouse clicks, and screen refreshes, it’s critical to remember that many concurrent application loads and screen refreshes can lead to spikes. Also, contention over network resources can still occur. Many IT organizations find that their requirement for network capacity is not diminished by thin client migration and, in fact, may go up. In virtualized thin client environments, in which each thin client is granted a “slice” of a virtual machine in order to replicate a complete PC experience, additional server capacity to service all these virtual machines must be considered. If the user’s virtual machine goes down in this 1 slice to 1 thin client scenario, the user is down until an IT pro can locate and repair “their” virtual machine.
  • Directly-attached peripheral device issues: Directly-attached peripheral devices (printers and USB devices) can be problematical in a thin-client environment. Many thin clients lack USB ports (or allow administrators to shut them off) and often lack the capacity to install specific device drivers, especially for unique devices.
  • Psychological hurdles: One of your biggest challenges may be changing users’ mindsets. Some users might vehemently resist losing “their” PC, on which they’ve installed their favorite games or screensavers and has become as personal to them as the photos on their office wall.

Planning and implementing a thin client migration

For organizations that are driving towards Green IT and sustainability, or desire the manageability and security benefits of thin client computing, experts recommend that a thin client migration should include the following activities:

  • A thorough assessment: Thin client advocates recommend that implementations begin with a complete understanding of the application portfolio running on the desktops under consideration for migration. It’s key to inventory printers and peripherals and to understand how much disk storage each user would typically require. And, it’s important to understand the network protocols in use across the infrastructure, as many thin clients utilize specific protocols (e.g., Microsoft’s Remote Desktop Protocol) to exchange data with the client. It’s also critical to understand the user community’s characteristics; for instance, are they high-bandwidth “knowledge workers” who use their computers all day every day or low-intensity occasional users? Many thin client planners go a step further and perform individual performance monitoring to assess the usage characteristics of each thin client recipient.
  • A meticulous plan: Once the assessment is complete, planners must design a server-based computing scenario that incorporates the disk storage, printer access, and server or virtual machine architecture required to support the population’s thin clients. Some vendors offer tools to assist in server or virtual machine sizing, such as HP’s Sizer for VMware, that can assist in this exercise. Planners must also consider redundancy, as thin clients are dependent on the server environment.
  • A Proof of Concept (POC): Thin client providers universally agree that a thin client POC is essential. All the sizing and planning described above are by nature estimations, and an actual, controlled implementation on a selected population is required to test assumptions and learn how server-based computing works in your environment. Experienced technicians recommend analyzing POCs to look for server bottlenecks, network bottlenecks, and virtual machine configuration problems. By using built-in Microsoft tools such as perfmon or third-party tools, IT pros can tune the server, virtual machine, or network to assure successful migration.
  • Selective migration: Most analysts agree that thin client computing is not suitable for every desktop in the organization. Selective migration to a carefully evaluated group of users — usually in a staggered manner to ensure that issues can be resolved group by group — is also suggested.

Enhanced Green IT and ROI

For organizations wishing to save acquisition and operating costs, to enhance security and manageability, and to promote Green IT and sustainability, thin client computing is a key component of the puzzle. Applying a selective and rigorous methodology to the migration to thin clients will position IT teams to reap the enhanced Green IT and ROI benefits that this computing model offers.

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