What does the /disasterrecovery switch for Exchange 2000 Server Setup do?

The /disasterrecovery switch is the rough equivalent of the /r switch you used with Exchange Server 5.5. When you install Exchange 2000, the server has to register itself in the configuration naming context (NC) of the Active Directory (AD) forest in which the server resides. This action, of course, is in addition to the mundane installation work of copying DLLs and so forth. However, when you restore a failed server, you want to restore its Exchange configuration and databases, not reregister it in AD. To accomplish those goals, you use the Setup command with the /disasterrecovery switch. This switch reloads the Exchange binaries and rebuilds Exchange's registry information on that local machine. To recover a failed server, install Windows 2000, run the Setup command with the /disasterrecovery switch (choosing the same component configurations the server originally had), restore the databases (you do have a backup, don't you?), and reboot. The stores won't automatically mount when the server restarts. This behavior is a feature, not a bug; the requirement to manually mount the databases prevents you from accidentally overwriting the databases. To mount the databases, you must clear the Do not mount the store at start-up check box on the Database tab of the store properties.