You are an IT manager who must migrate the Exchange server of a newly purchased company into your own Exchange server. You’ve laid the groundwork, you believe, by re-creating all of the new mailboxes on your server. When everyone leaves for the night, you think you and your Exchange administrator will spend a few hours migrating the old mailboxes into the new.

It should be easy, but most migrations rarely are.

Our article “Case study: Exchange directory sync” details the difficulties involved in synchronization of Exchange directories between Gartner (our then parent company) and TechRepublic. Completing a full migration of one Exchange server into another can be even more problematic.

In this article, TechRepublic’s Exchange server administrator Mike Laun describes how to accomplish a flawless Exchange migration, including tips on how to accomplish the task without losing any data.

Among the list of considerations are how to:

  • Use Exmerge, a utility to combine mailboxes.
  • Queue incoming mail so it won’t be lost during the transition.
  • Deal with user subscriptions to listservs.
  • Include new domain names on the Internet Mail Service.
  • Migrate public resources like folders and conference rooms.
  • Sort out and re-create distribution lists.
  • Reconfigure client profiles at the user machine.

Here is how Laun avoided these major pitfalls during the migration of the two Exchange 5.5 servers.

This is part one of a series on Exchange migration

This article is the first in a two-part series that covers migrating the mailboxes from one server into another without losing incoming and existing data. Next week, we will describe typical complications to avoid.

Using Swiss Army knife of the Exchange Administrator
When TechRepublic initially acquired the Minneapolis company in August 2000, Laun set up an Exchange directory synchronization similar to what had been done with Gartner. When Gartner bought TechRepublic, both companies wanted everyone in both mail directories—but both domains needed to remain separate. The same was true for the Minneapolis directory synchronization. Later, it was decided to fully integrate the mail systems of TechRepublic and the Minneapolis company.

The Gartner directory synchronization phase presented its own set of challenges and suffered from lack of well-written documentation for the InterOrg Synchronization Tool in Microsoft’s BackOffice Resource Kit (BORK). There were other complications due to the way Exchange views the organizational structure of a business.

“We are under different organizational names [Gartner and TechRepublic], and Microsoft didn’t plan very well for this,” said James Browning, research director for the Small, Medium Enterprise Research Group at Gartner. “Interorganizational synchronization is a very complicated process within Microsoft Exchange…that is where the problem lies.”

Laun used Exmerge, another Microsoft tool from the BORK for the bulk of his integration tasks in Minneapolis. Senior Web operations engineer Dom Bosco calls the Exmerge tool the “Swiss Army knife of the Exchange Administrator.”

Laun used Exmerge to take all of the mail messages, calendar items, notes, and other database information from the old Exchange server and place them in individual PST files for each mailbox. Those PST files were then merged into new mailbox files on the new Exchange server.

The new server is a part of the existing Exchange server, in this case, at TechRepublic.

Watch out for unintended user effects
While Exmerge is a great tool that will save your Exchange administrator lots of time and effort, it does have some drawbacks for the end user.

“Any kind of calendaring information that you had that was a reoccurring appointment will have lost the association between reoccurring appointments and their mailboxes,” Laun said. The affected users now have to delete their recurring appointments and accept new, updated appointments. The new recurring appointments will resume functioning.

“For people who have pretty busy calendars, that’s a pretty big deal,” Laun said. Members of senior management often have the most involved calendars, but they often have administrative assistants to maintain their complex schedules. That administrative assistant, who will suddenly face a lot of extra work, should be forewarned and prepared.

Getting all the data all the time
IT managers also need to be prepared for the task of transferring all the valuable data the Exchange database holds to the new Exchange server during the migration. Meanwhile, new data is arriving.

All the mailboxes need to be re-created on the new server before the switch is made. Then, it is simply a matter of switching the IP address to the new server, Laun said. This procedure stops incoming mail from going to the old server and redirects it to the new server.

It typically takes about an hour to physically make that switch, however, so it needs to be done well after working hours.

In TechRepublic’s case, the Minneapolis office is using a Trend Micro InterScan VirusWall that queues incoming messages. More than 600 messages were collected during the hour it took to make the switch.

Laun intentionally planned the switch at about 3 A.M., but that is the time when many listservs send out their messages. This illustrates another effect the migration of mail systems has on the end user.

Many listservs will accept an “unsubscribe” command from a user’s old account but not from his or her new account. If the user doesn’t unsubscribe before the switch, and most won’t, then the user needs to contact the Web master of the list and have the Web master unsubscribe the user before the user resubscribes under his or her new address. This strategy will also prevent duplicate messages in the future.

Exchange info about Exchange

Have you had to migrate one Exchange server into another? Was it easier or harder than it was for Mike Laun? Share your thoughts on the matter in a discussion below or send us a note.