What's the Ds2mb process?
Microsoft IIS uses a proprietary configuration mechanism called the metabase, which IIS uses to store almost all its configuration data. Think of the metabase as a cross between Active Directory (AD) and the Windows registry—the metabase contains elements from both AD and the registry.
Much of Exchange 2000 Server's functionality is built on top of IIS. For example, the SMTP, POP3, IMAP4, and HTTP mail interfaces all rely on core protocol components that ship with IIS. However, Exchange 2000 uses AD to store its configuration information. Every 15 minutes, the Ds2mb process synchronizes settings between the Exchange configuration objects in AD and the corresponding objects in a local computer's IIS metabase. If these objects aren't in sync, the metabase and AD will have different settings. For example, Exchange might think that a particular virtual Outlook Web Access (OWA) server has a certain URL, but the metabase might have a different URL specified—and IIS will use what's in the metabase. To avoid such conflicts, you need to use Exchange System Manager (ESM) to make changes to Exchange objects; Ds2mb then makes the corresponding changes in the metabase. Ds2mb is a one-way process, so changes you make manually to the metabase with the Microsoft Management Console (MMC) Internet Services Manager won't be reflected in the Exchange configuration objects.