Selecting Migration Types in MigrationWiz: Type Descriptions
Once you have created and populated your migration project, MigrationWiz provides five migration types. The five allow you to test and verify your connections, complete the migration either in stages or in a single pass, and then allows you to capture and migrate items that may have failed to migrate the first time around.
Following are descriptions of each migration type.
1. Verify credentials
This process checks the credentials for migration at both the Source and the Destination. Verifying credentials will not migrate any data or consume any licenses.
This process will perform the following actions:
- It will check that the mailbox exists on the Source.
- If using admin credentials at the Source (these are entered when creating the project), it will verify those credentials.
- If not using admin credentials at the Source, and instead entering passwords for each mailbox, it will verify those credentials.
- It will check that the mailbox exists on the Destination.
- If using admin credentials at the Destination (these are entered when creating the project), it will verify those credentials.
- If not using admin credentials at the Destination, and instead entering passwords for each mailbox, it will verify those credentials.
2. Trial Migration
A Trial Migration will migrate a very small amount of data in order to test that the project has been created properly and that the mailboxes have been entered correctly. It is completely free, and can be performed an unlimited number of times. Each Trial Migration will perform the following:
- Trial migrations verify credentials at both the source and destination.
- Trial mailbox migrations recreate the entire folder hierarchy on the destination, based on what is defined at the source.
- Trial migrations migrate only up to ten items in each folder, and up to a total of 10MB of data.
- Important: For Public folder migrations, the Trial migration only migrates the current folder and does not scan sub-folders. No data is migrated, nor is an error message shown. Upon running behind the scenes, the trial migration on public folders will show a Success message.
3. Pre-Stage Migration
A Pre-Stage Migration pre-fills a Destination mailbox with mail only migrated items, as defined by the Pre-Stage Migration settings chosen. A Pre-Stage Migration is typically part of a multi-pass migration strategy. It occurs before the MX record cutover, and is a great way to pre-fill the majority of the end users' data into their future Destination mailboxes while they are still using their old email system. It has no impact on the end users, and is a highly recommended strategy to follow since the majority of data is migrated over prior to MX record cutover. Typically only mail items older than three months are included in the Pre-Stage Migration, because these items are unlikely to change.
When performing a Pre-Stage Migration, it is important to understand that MigrationWiz is a migration solution and not a synchronization solution. With this in mind, it will not propagate updates, deletes, or moves of the items previously migrated in the first migration pass because we do not have “live” monitoring of changes (as with a sync agent), and we cannot handle scenarios like conflict resolution without user interaction.
Here is what would happen after a Full (Delta) Pass, if items previously migrated to Destination have been:
Deleted at the Source: The Destination will keep containing these deleted items. We cannot propagate deletes (e.g., if an item is archived at the Source, it will look like a delete and we can’t delete the item at the Destination).
Moved from Folder A to another Folder B: These items will be duplicated at the Destination, they will be both in Folder A and in Folder B at the Destination.
Updated at the Source: These items will not be updated at the Destination. There is no process by which the calendars, contacts, tasks, etc., can be updated. This would require conflict resolution, which is only possible with a synchronization solution.
Instead, MigrationWiz watermarks all migrated items so as to avoid remigrating any items in subsequent passes.
This multi-pass migration strategy typically follows an order of events similar to this:
- First pass (Pre-Stage): Migrate ONLY mail items that are older than three months. The Pre-Stage migration is performed one to two weeks before MX record cutover (times vary, dependent upon the number of mailboxes being migrated and the size of the mailboxes).
- Perform the MX record cutover.
- Second pass (Full or Delta): Migrate all items, with no date filters. This pass is performed after the TTL expires.
Note: Changing MX records in DNS to point to the new system is not effective immediately, and is subject to replication delays. Wait for the TTL (aka Time To Live) to expire. Until then, email systems on the internet may continue to deliver to the old system.
- Optional Third pass (Full or Delta): Migrate all items, with no date filters. This pass is performed two or three days after the MX record cutover. This picks up any residual mail that was still delivered to the old mail system after the MX record cutover, due to slow DNS internet propagation.
4. Full/Delta Migration
Both Full and Delta migrations have the same settings in MigrationWiz. With both migration types, the migration has no date filters, and all items are migrated.
With a Full Migration, everything is migrated in one pass. For example, a single pass migration (Big Bang) strategy will move the entire mailbox in one pass, after MX records are cutover. A typical scenario consists in cutting over on a Friday evening and migrating during the weekend.
With a Delta Migration, which is performed after a Pre-Stage Migration and is part of a multi-pass migration strategy, it is possible to resubmit a mailbox or mailboxes to perform a differential migration pass. MigrationWiz will automatically find items that haven't yet been migrated since the first pass, and migrates only those. In other words, a Delta pass will find and migrate residual items. In most cases, a Delta pass will complete much faster than the initial pass. In a Delta pass, MigrationWiz will continue the migration from where it left off and cause no duplicates to be created at the Destination, which means that all items which were not migrated in the first pass or were created after/during the first pass will be migrated.
5. Retry errors
This is another attempt to migrate any items that previously failed to migrate. It will not migrate any successfully migrated items. It will not consume any more licenses.
Only submit mailboxes in the Retry errrors mode if they satisfy both of the following conditions:
- The last migration completed successfully.
- The mailbox contains at least one error.