Software platform migrations can be a painful and expensive undertaking. Oftentimes, it's helpful to first take a look at what others have done to get an idea about what works -- and what doesn't.
Migration warrior: Antonio Martinez, MCSE, Grupo Scanda consultancy
Organization: Pemex Gas and Basic Petrochemistry, Mexico City
Number of users/mailboxes: 4,500
Number of servers dedicated to messaging:
Current version of Exchange: Exchange Server 2003
Messaging system you migrated from: HP OpenMail
How long did the migration take: Six months
Describe the migration: When this migration project was born in February 2002, the initial scope was to migrate from Hewlett-Packard's OpenMail to Exchange 2000.
The first problem came while migrating users' mailboxes, because of a lack of a coexistence method between OpenMail and Exchange 2000. Microsoft does not provide any type of connector to provide this type of coexistence.
Since Hewlett-Packard only supports one connector between OpenMail and Exchange 5.5, the first step in the migration process was a Windows 2000 Active Directory implementation.
The second step was implementation of an Exchange 5.5 organization in the Windows 2000 domain. The third step was implanting Exchange 2000 in the Exchange 5.5 organization.
The original design of the Exchange 2000 migration was for three sites -- one for each regional headquarters: north, central and south. But the problem was the limitation of the OpenMail connector to replicate mailbox accounts between sites, so the original design was changed to consider only one site or administrative group.
All of these activities were developed during a period of six months; HP provided the connector and the OpenMail consultant to install the relevant software. Microsoft Consulting Services played the role of quality assurance during this project.
The last phase was the Outlook deployment on the 4,500 clients.
Finally, when Exchange Server 2003 was released during the Exchange client deployment, we decided to pause the deployment and migrate immediately to Exchange 2003 and Windows Server 2003.
That process was also done in three phases. The first was the Active Directory migration from Windows 2000 Server to Windows Server 2003, which involved schema preparation. The second phase was the schema preparation to support Exchange 2003. The Exchange migration was an in-place upgrade of Exchange clusters -- again, done separately for the sites in Mexico City, Monterrey Nuevo Leon and Villahermosa Tabasco.
The cluster migration was a difficult process because it required a special series of key steps. There was little information about migrations to Exchange 2003 clusters on Microsoft's Web site, so I posted a ticket in the Microsoft Support Center, which later responded with guidelines.