This article is an excerpt from the Exchange Server 2010 to 2013 Migration Guide.
With co-existence established and the Client Access namespaces cut over to Exchange Server 2013 we can begin the mailbox migrations.
When you’re planning a mailbox migration it helps to know what you’re dealing with in terms of number of mailboxes, their sizes, and the number of items they contain. To gather this information I recommend using the Get-MailboxReport.ps1 script.
In earlier versions of Exchange such as 2003 and 2007 the mailbox migration process was an interactive task that required the administrator to test how much mailbox data they could move per hour, break up the mailboxes into migration groups, time the moves to occur out of business hours, and communicate to end users that their mailbox would be unavailable for what was often a several hour period.
In addition to this, care had to be taken not to move so much data in one period that the transaction log volumes on the destination Exchange server ran out of disk space.
Exchange Server 2013 will apply self-management of its resources when processing mailbox moves, backing off when required due to server load or to allow log replication to catch up. Move requests can be issued and allowed to run without the administrator needing to micro-manage the process, with only occasional monitoring required and some intervention at the end to complete the moves.
And in a scenario where mailboxes are being migrated from Exchange 2010 to 2013 the moves are processed as online moves, which do not require the user’s mailbox to be offline for the whole move process, only the final completion stage.
For the Exchange Server Pro organization the migration follows this process:
- Run the Get-MailboxReport.ps1 script
- Choose a sample of pilot users, with the rest of the mailboxes assigned to a small number of batches that increase in size from first to last
- Migrate the pilot mailboxes
- Migrate each subsequent batch
You can learn more about the migration process here:
In each case the administrator running the migration only needs to:
- Create and start each migration batch
- Monitor the progress of the migration batch
- When ready, notify end users of a brief outage for that evening and then complete the migration batch
- Repeat for the next batch
With the mailbox migrations complete the next step is to look at public folder migration.
For more information see the Exchange Server 2010 to 2013 Migration Guide.