Enterprise Vault Migrations Using In-Flight Stub Rehydration: Overview
This overview provides general guidance for using BitTitan MigrationWiz to execute an archive migration from Enterprise Vault using in-flight stub rehydration. In-flight stub rehydration is a process provided by BitTitan MigrationWiz.
Rehydrating stubs reconstructs the archived email message by recombining the stub with the original message body along with attachments, if any. Rehydrating stubs is necessary when migrating archived email, contacts, and calendar items out of a legacy archiving system, if those archives rely on stubs in Exchange.
Stub rehydration has traditionally taken place on the Source system or on the Destination system, but both of these approaches have drawbacks.
MigrationWiz overcomes these issues by introducing in-flight stub rehydration (IFSR), which executes stub rehydration while the migration is in progress. This provides efficiencies, as well as avoiding the issues created with Source- and Destination-based rehydration.
Enterprise archive migrations
Migrating an email archive is challenging because, if improperly done, you can break the link between the stubs and their associated email, which makes the stubs useless and the archived messages orphans, which is a potentially catastrophic outcome.
Failing to plan for stub management can bring pain to your end users, especially to the IT team supporting them. The central concern is If I have stubs, what do I do with them? You can choose to ignore stubs and simply delete them, but most commonly you'll want to preserve them. The best option, then, is rehydrating the stubs and moving the reconstituted messages to your new Destination.
In-Flight stub rehydration workflow
In-flight stub rehydration follows a complex workflow that touches four environments: the Source and Destination environments, Enterprise Vault file and database servers, and MigrationWiz (see Figure 1). Fortunately, MigrationWiz hides almost all of the complexity and requires only that you correctly set up, configure, and execute your MigrationWiz project.
Here is an overview of the IFSR workflow, which is diagramed in Figure 1. Numbers in the diagram are referenced in the text following.
Figure 1. In-flight stub rehydration workflow.
The customer Source site has an Exchange Server, which contains the message stubs. It also contains a virtual machine, on which the extractor agent is installed. You download an install the extractor from the MigrationWiz UI while setting up your migration project.
The Destination system can be Office 365 mailboxes or Exchange Online archive mailboxes, or other message system of choice.
Limitations of in-flight stub rehydration
While stub rehydration is feasible in nearly all migration scenarios, to implement in-flight stub rehydration using MigrationWiz, there are some limitations:
For more information, see the white paper Enterprise Archive Migration Overview.