Selecting an Edition

So, which edition is right for your needs? Standard, Enterprise, Datacenter, or Web? Deciding can be difficult because each offers specific advantages for specific applications. In the next four sections, you'll be introduced to the exact feature set provided by each edition and be provided with some recommendations for how each one can be best utilized.

If you're installing new servers, selecting the right edition of Windows Server 2003 is all you need to do, and most server manufacturers will be able to sell you a server with the correct version preinstalled. However, you'll probably be upgrading a fair number of servers from previous editions of Windows, so you'll need to play close attention to edition features and compatibility to select the appropriate version for your upgrades.

To compare Windows Server 2003 editions to previous editions of Windows or to review the differences between Windows NT and Windows 2000 editions, visit www.samspublishing.com and enter this book's ISBN number (no hyphens or parentheses) in the Search field; then click the book's cover image to access the book details page. Click the Web Resources link in the More Information section, and locate article ID# A010101.

The information in the next four sections applies only to 32-bit versions of Windows Server 2003; 64-bit versions, written for Intel's Itanium processor family, have slightly different capabilities and limitations. Note that not all editions of Windows Server 2003 are available for the Itanium family.

• For more details on the 64-bit editions of Windows Server 2003 and how they differ from their 32-bit counterparts, see "Significant Differences," p. 259.

Windows Server 2003, Standard Edition

Standard Edition is the basic edition of Windows Server 2003 and is the one you'll likely use the most. It's suited to the broadest range of applications, particularly file serving, print serving, and low-demand application serving. Standard Edition supports a maximum of 4GB of server RAM, 4TB of disk space, and up to four processors.

Standard Edition supports the entire basic set of Windows Server 2003 features. It can act as a domain controller, public key infrastructure (PKI) server, and so forth. It does not offer clustering capabilities, aside from Network Load Balancing (NLB), which is included with all editions of Windows Server 2003.

• For information on NLB and its capabilities, see "Network Load Balancing," p. 207.

Standard Edition cannot host Microsoft Metadirectory Services (MMS), a technology used to integrate multiple directory services, such as Active Directory, Novell Directory Services (NDS), and so forth. Standard Edition also lacks support for advanced scalability features, including the capability to add memory to a server while it's running, non-uniform memory access, and so on. Standard Edition does, however, include Terminal Services, but it does not support the Terminal Server Session Directory?a feature that allows users to easily reconnect a disconnected Terminal Services session hosted by a farm of Terminal Services computers.

Where is Standard Edition best used? In a broad variety of applications:

• As a file server? However, for critical files, you might want to use a server cluster capable of failover to ensure the constant availability of those files. Standard Edition doesn't support clustering.

• As a print server? As with files, mission-critical printing might be better hosted on a server cluster that supports failover, and Standard Server doesn't offer that option.

• As an application server for applications such as Exchange Server or SQL Server? However, environments with heavy application server usage, or environments that rely heavily on the services of these applications, might be better off on a cluster (for reliability) and Windows Server 2003, Enterprise Edition (for better memory support).

• As a Web server? However, Windows Server 2003, Web Edition might offer a less expensive alternative, particularly if your Web servers are typical in their feature requirements and don't need to be a domain controller or play another role that Web Edition doesn't support.

• As a domain controller? This is an ideal role for Standard Edition in any situation; although you can host domain controllers on clusters, the distributive nature of Active Directory makes doing so redundant, so Standard Edition offers all the features you need.

• As a network services server? For example, as a domain name service (DNS) or Dynamic Host Configuration Protocol (DHCP) server. Generally, these functions are not hosted on a cluster, making Standard Edition the perfect platform.

Standard Edition is especially ideal as an all-purpose platform for smaller environments, where advanced features like clustering or large memory support aren't required.

Windows Server 2003, Enterprise Edition

Windows Server 2003, Enterprise Edition fills many of the same roles as Standard Edition and adds features primarily geared toward improving reliability and scalability. Enterprise Edition supports a maximum of eight processors, which is double Standard Edition's capability. Enterprise Edition also supports Address Windows Extensions (AWE), providing an extra gigabyte of memory to applications by reserving only 1GB for Windows, rather than Standard Edition's 2GB/2GB split between the operating system and applications.

Enterprise Edition also supports Windows Clustering, allowing you to build failover clusters with two nodes. The Cluster Service allows you to create clustered file shares and clustered printers and supports clustered applications, such as SQL Server Enterprise Edition and Exchange Server Enterprise Edition. The Cluster Service even enables you to cluster applications that aren't specifically designed for clustering, provided they meet certain criteria spelled out in the Windows online documentation.

Enterprise Edition can also host Microsoft Metadirectory Services (MMS), allowing large organizations to integrate multiple heterogeneous directories.

Enterprise Edition ups the ante for scalability and reliability, as well. Enterprise Edition is available in a 64-bit edition for Intel's Itanium family of 64-bit processors. With the proper server hardware support, Enterprise Edition also supports hot-add memory, which is the capability to add server memory while the server is running, and non-uniform memory access (NUMA). NUMA is a fairly new concept in the Windows world and occurs only in servers that are built with multiple separate processor busses. Each bus has its own memory, which is accessible at very high speeds to processors on that bus. When processors must access memory on other busses, however, access is slower. This disparity between memory access times is referred to as NUMA. High-end servers will be built with this multiple-bus architecture to provide faster memory access times.

Finally, Enterprise Edition supports the Terminal Server Session Directory, which makes working with large Terminal Services server farms more intuitive for users.

• For more information on the Terminal Server Session Directory, see "Terminal Server Session Directory," p. 194.

Enterprise Edition is an ideal platform for high-demand, mission-critical applications, including

• Mission-critical shared files

• Mission-critical printer access

• High-demand or mission-critical applications such as SQL Server or Exchange Server

• Any applications that can benefit from the 3GB memory space supported by Enterprise Edition

Windows Server 2003, Datacenter Edition

Datacenter Edition builds on the feature set offered by Enterprise Edition and eliminates a few features that aren't considered appropriate for a large enterprise data center. For example, Datacenter does not support the Internet Connection Firewall or Internet Connection Sharing, two features designed to make Windows an Internet gateway for network clients. Both features are, however, supported by Standard Edition and Enterprise Edition.

Datacenter Edition adds support for up to 64GB of server RAM and up to 32-way processor support. These features require a specialized Hardware Abstraction Layer (HAL), which is provided by the server hardware manufacturer. Datacenter Edition's Cluster Service supports eight-way clusters, enabling you to build more complex failover clusters for mission-critical applications.

Although Datacenter Edition does provide a "bigger and better" product over Enterprise Edition and Standard Edition, that's not really the point of Datacenter Edition. The real point of Datacenter Edition is much more important and is almost philosophical in nature: You can only buy Datacenter in conjunction with an approved server, directly from an approved server vendor. To receive product support for Datacenter Edition, you must contact the server vendor, not Microsoft, and you cannot make any hardware changes to the server without prior approval from the server vendor.

This philosophy is at the heart of Microsoft's Datacenter program, which is designed to provide you with a server that can remain up and running 99.999% of the time?the magical "five nines" reliability number that enterprises demand. In case you're wondering, that's slightly less than nine hours of downtime per year.

Everything about the Datacenter program is focused on reliability:

• All hardware included in a Datacenter-approved server must meet rigid Microsoft standards and pass a battery of compatibility and reliability tests.

• All device drivers must be certified and digitally signed by Microsoft.

• Customers cannot make any unauthorized changes to the server hardware. This includes every aspect of the hardware. For example, if you purchase a quad-processor Datacenter system, you can't upgrade it to eight processors unless that's also a certified, supported configuration from your vendor.

As we mentioned earlier, Datacenter Edition is sold only through server vendors and is sold preinstalled only on certified server hardware. You'll find that the hardware on which Datacenter Edition is offered is usually the highest of the high end: multiprocessor computers with copious amounts of RAM, redundant network adapters and power supplies, and so forth. Datacenter Edition computers are almost always clustered for higher availability and generally run an enterprise's most mission-critical applications.

Microsoft takes more care with updates for Datacenter Edition, too. Operating system service packs and hot fixes for Datacenter Edition generally lag behind such releases for other editions of Windows Server 2003 because Microsoft and its server vendor partners rigorously test all fixes for the operating system to ensure nothing will interfere with Datacenter Edition's 99.999% reliability record.

Likely applications for Datacenter Edition include any high-volume, mission-critical use, such as the following:

• Massive file and print servers

• Large, non-partitionable databases

• Consolidated servers that each assume the functionality of multiple lesser servers

• Other enterprise applications that simply cannot be unavailable

Expect to pay for Datacenter Edition's reliability. Although Microsoft doesn't publish pricing for Datacenter Edition are established by the server vendors who resell the operating system?the operating system itself, not to mention the high-end server hardware on which it runs, commands a premium price. If you're interested in finding out exactly how much, contact your local Hewlett-Packard or IBM sales representative. Tell him you're interested in purchasing a Datacenter Edition computer and watch his ears perk up! In fact, the sheer expense of Datacenter Edition and the associated server hardware makes it the least-deployed version of Windows. Many administrators might go their entire career without working on a Datacenter Edition, even in fairly large enterprises.

Windows Server 2003, Web Edition

In recent years, Microsoft has taken a pummeling in the Web server business. At one time, IIS and Windows NT Server 4.0 was the most popular commercial Web server platform; today, Windows 2000 Server and Windows Server 2003 are fighting against a wave of free and inexpensive versions of the Linux operating system and Apache Web server software. Microsoft argues that such servers don't come with the support that a multi-billion dollar company like Microsoft can provide; fans of Linux/Apache solutions say, "Who cares?" As a result, Microsoft has worked hard to provide a lower-cost version of Windows that's optimized to be a high-speed Web server. Although lower-cost certainly doesn't beat free, it does help close the gap and make potential buyers look at the additional features IIS offers, as well as the support Microsoft can provide. Microsoft's lower-cost Web server solution is Windows Server 2003, Web Edition.

Windows Server 2003, Web Edition's lower price doesn't mean you're getting a free lunch, though. For example, Web Edition lacks the other Windows Server 2003 editions' Enterprise UDDI (Universal Data Definition Interface) services, which is an industry-standard way of publishing and locating information about XML Web services. And, even though Web Edition can be a member of an Active Directory domain, it can't be a domain controller. Web Edition also lacks support for Microsoft Clustering, although it does include the NLB software that's appropriate for creating Web farms.

Web Edition lacks some of the communication features of the other editions, including the Internet Authentication Service (IAS), network bridging, Internet Connection Sharing, and the Internet Connection Firewall. Web Edition cannot host MMS. Unlike all other editions of Windows Server 2003, Web Edition does not support removable storage management, Fax Services, Remote Installation Services, Windows Media Services, or Services for Macintosh?all features that are useful on a network but are not specifically useful for a Web server. Although Web Edition does include Terminal Services' Remote Desktop for Administration, allowing you to remotely control your Web Edition computers, Web Edition doesn't support any other uses of the Terminal Services technologies.

Web Edition also lacks the scalability and reliability features of Enterprise Edition and Datacenter Edition, including a 64-bit edition, hot add memory, and NUMA support. Web Edition's scalability and reliability derives entirely from the inherently reliable and scalable nature of Web farms, which you can build using the included NLB software.

Web Edition's potential applications? Just one: as a Web server, either in the Internet or on your company's intranet. With more and more applications being implemented on Web servers, though, Web Edition's lack of breadth can hardly be considered a limitation. And if you're accustomed to paying a couple thousand bucks for the basic edition of Windows to run your Web servers, Web Edition's sub-$1,000 list price should be a welcome change.