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Reference Materials for Migration 8.15 - Tips and Tricks

Introduction Environment Assessment, Planning, and Testing Basic Migration Steps Considerations for Active Directory Migration and Resource Update Considerations for Exchange Migration Preferred Settings for the Directory Synchronization Agent Directory Synchronization Agent Placement Indexing Service Attributes Full Directory Resynchronization Conclusion Environment Preparation Checklist Exchange Migration without Trusts Active Directory Migration without Trusts

Directory Synchronization Agent Placement

It is not recommended to install the Directory Synchronization Agent on the domain controller, Exchange Server, or console machine to avoid possible server and agent performance degradation. The best practice is to install the Directory Synchronization Agent on a dedicated server that has good connectivity to both the source and the target domains being synchronized. For the list of supported operating systems, see the System Requirements and Access Rights document.

Indexing Service Attributes

When synchronizing objects, the Directory Synchronization Agent populates the objects' attributes specified as the service attributes in Migration Manager with matching and auxiliary information. It is required to index the service attributes in Active Directory to improve the Directory Synchronization Agent performance.

For more information about the service attributes, refer to the Quest Migration Manager for Active Directory—User Guide.

For more information about Directory Synchronization Agent performance, refer to the Migration Manager for Active Directory - Improving Directory Synchronization Performance document available at

Full Directory Resynchronization

Normally, no resynchronizations are required after the initial synchronization is complete. The ongoing synchronization process brings only changes made since the last agent’s session to the opposite directory. Changes are identified by changed Update Sequence Numbers (USNs).

However, in certain cases you might consider full resynchronization for a job. These are described in further detail below.

  • Group membership for the groups may not be updated correctly if you have migrated groups before user accounts are migrated to the target domain (see the Linked Attributes and Group Migration topic.) Running full resynchronization after all objects are migrated will help resolve all the links.
  • If you have modified a directory synchronization job configuration after the job has already been started, full re-synchronization is required. You will be prompted by Migration Manager to restart the Directory Synchronization Agent processing the job. The initial synchronization (full source and target directories enumeration and synchronization) will take place.

Note that full directory resynchronization is a time-consuming operation. During the operation, the source and target directories are fully re-enumerated, and then the objects within the specified synchronization scope are matched and synchronized. The process may take up to 10 hours for 100,000 objects, depending on your hardware. You should plan for full re-synchronization and avoid it until it is actually required.


Active Directory and Exchange migrations are monumental tasks. This is especially true for large distributed and complex environments. It is essential that a solid discovery and analysis be completed on the entire enterprise prior to migration. All testing should be performed in an environment that mirrors the production environment as exactly as possible.

To make migration easier, first perform Active Directory migration, ensure that Active Directory is stabilized, and then go forward with the Exchange migration.

Although no two projects are exactly the same, this document outlines some of the key factors for ensuring a successful Active Directory and Exchange migration.

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