This article describes the key points of migration from Exchange Server 2010/2013 to Exchange Server 2016.

The general procedure of migration is depicted in the diagram below.

The key points of migration are:

  • In each phase, a lot of tasks may be scheduled in the Task Manager, depending on the number of Exchange objects being migrated. These tasks, as any other tasks, are executed by the Task Manager so that the performance and UI responsiveness of CloudBlue Commerce do not change significantly. There is a limit on the number of tasks that can be executed in parallel. As a result, only a number of these migration tasks are executed at the same time, while the other migration tasks are in a queue and are not executed.
  • In the Task Manager, there may be a lot of migration tasks whose start time is in the future. Such tasks are scheduled intentionally to be started when their move requests complete on the Exchange Server side.
  • A migration task is scheduled for a purpose. Do not cancel migration tasks as it will break the consistency of migration.
  • The most time-consuming work is mailbox content migration. The more mailbox content you need to migrate, the longer the migration will be.
    • Mailbox content is migrated by Exchange Server only, not by CloudBlue Commerce. The only effect on CloudBlue Commerce is that a number of migration tasks are scheduled in the Task Manager. These migration tasks are in a queue and wait for their move requests to complete on the Exchange Server side.
    • The speed of mailbox content migration heavily depends on the bandwidth of the network your Exchange Mailbox servers are connected to.
    • To estimate the overall time of migration, divide the size of mailbox content (in gigabytes) by the network bandwidth (in gigabytes per unit of time), using the numbers of your CloudBlue Commerce installation.
      Note: To obtain the size of mailbox content, use the SQL query from the internal part of this article or ask your technical account manager to provide it. It is safe to execute this SQL query during business hours.

Internal Content
See this article.