With multiprocessor support for 8-way Pentium and XEON processors, memory-tuning options via the /3GB switch and /USERVA switch, and IPSec server communication between Exchange 2003 front-end and back-end servers, Windows Server 2003 is the operating system of choice. Although Exchange Server 2003 can be run on Windows 2000 Server SP3 and later, Windows Server 2003 should be run to take advantage of enterprise class features, such as enhanced reliability, remote access, and server clustering.
Windows Server 2003 improves on the server platform reliability delivered in Windows 2000 Server. With improvements in the underlying server architecture, Active Directory performance, management, and maintenance tools, as well as support for new technologies such as the Volume Shadow Copy Service (VSS) and server clustering, Windows Server 2003 represents major enhancements to the reliability and scalability of Exchange 2003. Cluster Fail Over and Fail Back technology and snapshot backup technology with VSS will dramatically reduce server downtime and provide creative options for disaster recovery. Because the reliability of the server platform has been significantly improved, organizations can look at reducing costs by reducing the amount of money spent on purchasing and supporting multiple servers and network infrastructure.
Windows Server 2003 also significantly improves remote access capability for Exchange users. One of the most noted improvements is the capability for Outlook 2003 users to communicate securely with Exchange servers via RPC over an HTTP connection. This connection over the Internet eliminates the need for tunneling technologies such as Virtual Private Networks (VPNs), smart cards, and other secure access technologies. Coupled with the new Outlook 2003 Cached mode, which allows users to have a full copy of their mailboxes available at all times and eliminates the need for a continuous connection to the email server or network, RPC over HTTP provides a secure and reliable method for remote access across slow or problematic network connections. This option is available only with Windows 2003 Server.
Clustering services in Windows Server 2003 provide dramatic improvements by enhancing existing features found in previous versions and also offering new key options. Unlike Windows 2000 Server cluster support for only two nodes, Windows Server 2003 Enterprise Edition and Datacenter Edition provide support for up to 8-node clustering. Clusters can be created in various active/passive node configurations, such as seven active/one passive or four active/four passive or in an Active/Passive with as little as one Passive node.
With preconfigurations, remote administration, and default settings, installation and setup are easier and more robust; basic server clusters can be up and running quickly, and with fewer server reboots.
Clustering services are also closely integrated with Active Directory. This tight integration includes features such as Kerberos authentication, delegation, and security, and Active Directory-aware service integration with other services that publish information to Active Directory.
Enhanced network features such as improved failover logic, media sense detection, and multicast heartbeats provide greater failover capabilities and high system uptime. In addition, all internal cluster communications are signed and secure. With the addition of real-time monitoring tools, such as ClusDiag and ClusterRecovery, support personnel can locate failures and possible future cluster problems.