Both of the preceding migration scenarios are a combination of two other migration scenarios: Active Directory Migration and Exchange Migration.
All descriptions and recommendations for the migration steps in the Active Directory Migration and Exchange Migration scenarios are fully applicable to the combined Active Directory and Exchange migration scenario. For descriptions of the migration steps, refer to theActive Directory Migration and Exchange Migration topics.
Additional best practices and recommendations for Active Directory migration, resource update, and Exchange migration are described in the following topics: Considerations for Active Directory Migration and Resource Update and Considerations for Exchange Migration.
If only one-way directory, public folder, calendar, and free/busy synchronization is established, Migration Manager does not make changes to the source environment.
During the account migration phase, Migration Manager just reads data from source and applies it to target. That means that until you disable source accounts, if migration issues arise, users can log in back to source. We recommend that you keep source accounts for a period of time after the migration is finished.
Migration Manager is designed so you can roll back any changes made to the environment at any step of the migration process, as follows:
Return to the Source Accounts
The easiest way to roll back is to start using source accounts again. You can start using source accounts at any stage of the migration process as long as you leave the source accounts’ permissions while processing the resources.
You can also undo the corresponding session in Migration Manager to roll back the account migration. This will delete the accounts created by the session on target. Merged accounts will be returned to the states they had before the migration.
CAUTION: When you undo a session from Migration Manager, all migrated accounts are removed from the target domain. But if you have already re-assigned permissions on the resources to the target accounts (that is, performed steps 3 and 5 described in the Active Directory Migration topic), each resource’s ACL after the session undo will contain unresolved SIDs of the deleted objects. Therefore, you should always return the target environment to its original state by performing permissions revert before doing a migration session rollback.
Permissions revert is done by the same wizards that were used to re-assign permissions to the target accounts.
NOTE: Migration Manager does not keep the information about permissions originally set to each object before the migration and resource updating. Revert procedures simply substitute target SIDs with the corresponding source SIDs.
Restore from Backup
If changes were made to the source environment that cannot be undone, use standard procedures to restore from backup. That’s why it is recommended that source and target environments be backed up with standard backup procedures. Ensure that you have the latest valid backup of your servers in both source and target.
We also encourage using Recovery Manager for Active Directory during all migration and post-migration activities to back up Active Directory. This allows online granular restoration of objects down to the attribute level without a domain controller reboot if they are accidentally deleted or corrupted.
Return to the Source Mailboxes
Users work with their source mailboxes until the mailbox is switched and the client profile is updated on the user workstation. After the mailbox is switched and client profile is updated, a user starts using the target mailbox. However, if for some reason you want the user to work with the source mailbox again, at any point of migration you can do the following:
For more information about the mailbox switch and the client profile undo, refer to the Quest Migration Manager for Exchange—User Guide.
Restore from Backup
If changes were made to the source environment that cannot be undone, use standard procedures to restore from backup.
We also encourage using Recovery Manager for Exchange during all migration and post-migration activities to back up source Exchange servers data. This allows online granular restoration of objects down to the message item level if they are accidentally deleted or corrupted.