Exchange 2000 Certified on Windows 2000 Datacenter Server

Microsoft, in conjunction with independent testing service VeriTest, has certified Exchange 2000 Enterprise Server for use with Windows 2000 Datacenter Server. When run on Datacenter servers, Exchange 2000 will support up to 32 processors and four-way clustering, allowing it to host many more users with greater reliability. This will be of greatest interest to large organizations and application solution providers (ASPs) who want to consolidate thousands of users onto a single server or cluster. However, Datacenter systems with Exchange 2000 will not be available until later this summer.

Although Exchange has taken a significant step forward in terms of reliability, the scalability of Exchange is still hampered for three reasons. First, Exchange 2000 does not support the use of Address Windowing Extensions, which means it cannot exploit the full 64GB of memory available on Datacenter’s Physical Address Extensions-based memory. Instead, Exchange is still limited to the 3GB large memory support first introduced in Windows NT 4.0 Server Enterprise Edition. Second, Exchange does not scale well beyond 16 processors because of limitations in its internal architecture. Third, limitations on Exchange’s Web Store database technology prevent large organizations, particularly ASPs who serve hundreds or thousands of small customers, from partitioning the database into units small enough to isolate customers’ data or allow for rapid data restoration. The time required to restore extremely large Exchange databases may exceed the brief time windows permitted by service-level agreements with their users. Solutions to these problems may not come until Microsoft ships a future 64-bit version of Exchange, code-named Kodiak (which is in turn based on a future version of SQL Server, code-named Yukon).