In last week's UPDATE, I outlined some of the improvements and changes that Exchange Server 2003 Service Pack 1 (SP1) introduces. The changes that seemed to attract the most interest from Microsoft TechEd 2004 attendees center on migration from Exchange Server 5.5. (Erik Ashby led three well-attended and highly rated TechEd sessions about Exchange 5.5 migration, and much of the talk in the "Meet the Technologist" cabana focused on the best way to accomplish migrations.) One of the most interesting aspects of Exchange 2003 SP1, therefore, is that it provides the capability to move mailboxes between Exchange 5.5 sites and Exchange 2003 or Exchange 2000 Server administrative groups in a mixed-mode Exchange organization.
Exchange 5.5 uses the X.500 distinguished name (DN) to name mailboxes. This DN contains the name of the mailbox's home site and mailbox server. Updating the portion of the DN that contains the mailbox server name is no problem; that capability has been around since Exchange 2000 shipped. Updating the home site name is a more complicated process but is necessary to enable cross-site mailbox moves. In order for a move to succeed, a great deal of behind-the-scenes juggling must take place so that the mailbox attributes will be squared away when the mailbox is moved to an Exchange 2003 server. Exchange 2003 SP1 contains five new or updated components and tools that make this process possible:
- The updated Exchange Server Deployment toolset (ExDeploy) sets out new guidelines for mixed-mode, cross-site migrations. These guidelines include references to other new tools and instructions for how to use them.
- The updated Active Directory Connector (ADC) takes into account the fact that you can now move an Exchange 5.5 mailbox to an Exchange 2003 server, and synchronizes mailbox attributes accordingly.
- The Object Rehome (aka LegacyDN) tool updates a mailbox's legacyExchangeDN property for custom recipients and distribution lists (DLs), basically back-patching references to moved objects. For example, if you move mailbox A, homed on an Exchange 5.5 server in site 1, to site 2, any DLs in site 1 that contain a reference to mailbox A will be broken. The Object Rehome tool updates those DLs. Updated DLs or custom recipients will be replicated as necessary for the changes to propagate.
- The Exchange Profile Redirector (aka Exchange Profile Update) tool accomplishes what would otherwise be an onerous task: fixing desktop clients’ Outlook profiles to reference the new mailbox server. When you move a mailbox within an administrative group, the Microsoft API (MAPI) referral mechanism typically updates the profile automatically, but this mechanism wasn’t designed to work across administrative groups. You can use the Exchange Profile Redirector tool to force the profile to point to the correct server. Users have to run this tool once only on their systems after they log in.
- The Exchange System Manager (ESM) Move Mailbox tool has been updated to allow and correctly handle cross-site moves.
Why are these enhancements generating so much buzz? Many organizations that want to migrate an Exchange 5.5 organization to Exchange 2003 also want to reduce the number of sites and servers they have. Doing so can save a considerable amount of administrative overhead and expense, but without the ability to move mailboxes between sites, there’s no good way to collapse sites. You can install an Exchange 2003 server in each site and move mailboxes to it, consolidating servers along the way, but site consolidation requires a bunch of additional hoop-jumping.
By unshackling cross-site mailbox moves, Microsoft obviously hopes to build further momentum toward Exchange 2003 migrations. Based on TechEd attendees' enthusiasm for SP1's new tools, that momentum seems like a safe bet. The new tools (as well as the SP1 Help files I mentioned last week) are available from the Microsoft "Downloads for Exchange Server 2003" Web site ( http://go.microsoft.com/fwlink/?linkid=25097 ). If you've been holding back from migrating until you could effectively move mailboxes between sites, you need wait no longer. Let me know how SP1 affects your migration schedule.
