We have a Hybrid setup with on-premises Exchange 2010 and Office 365. We intend to move a group of mailboxes back from Office 365 to our on-premises Exchange environment.
When I perform a Move Request command to move a mailbox, the request get queued. Some mailboxes are moved straight away, but for some mailboxes it takes up to 6 hours (!) before the status changes from 'queued' into 'moving'. I suspect that this mostly occurs for large mailboxes, larger than 1 Gb. I did not expect this behavior, and this makes the movement of mailboxes kind of unpredictable...
I have the following questions regarding this topic, which I hope somebody can help me with.
- Why are some mailboxes moved right away, and why does it take others to start moving after several hours?
- Does it have something to do with the mailbox size?
- How can I see why mailboxes are queued, and what the expected time is when a mailbox move is actually started? I've looked at the Move request log, but no information is shown there. Only a message that I have created a move request.
- Does Microsoft apply somekind of 'back pressure' mechanism that caused move requests to maintain queued until enough resources are available? If so, is any information about that publically available?
Many thanks for your help.