Exchange 2003 to Exchange 2010 Intra-forest Mailbox Moves

Hi

We have setup co-existence between Exchange 2003 and Exchange 2010 in our environment. We have things working in parallel and now we wish to move mailboxes from Exchange 2003 mailbox server to Exchange 2010 mailbox servers.  Since it’s a live environment, we want to ensure that the mailbox movement happens quickly and error free. We have around 8000 mailboxes with following configuration:

1. 100 Mailboxes – 1 GB size
2. 100 Mailboxes – 500 MB size
3. Rest Mailboxes – 200 MB

To plan mailbox moves, need to know the following:

1. Is there any difference in using EMC or EMS, any preferences (pros n cons)
2. If we use Powershell to bulk move mailboxes, will the mailbox moves batched together in one shot be moved in parallel (keeping in mind the limit configuredMaxActiveMovesPerSourceMDB, MaxActiveMovesPerTargetMDB,MaxActiveMovesPerSourceServer, MaxActiveMovesPerTargetServer parameters), OR the moves be queued sequentially?
3. Is there any difference from Network bandwidth perspective, if we move single mailbox at a time or multiple mailboxes simultaneously (meaning single mailbox move completes faster as compared to multiple mailbox moves taking longer time)?
4. What is the significance of MaxTotalMovesPerMRS parameter?
5. Is there a limit on number of parallel mailbox moves that can use Exchange 2003 servers (similar to what we have in Exchange 2010)?
6. What would be the best way to achieve maximum mailbox moves in parallel (using moving 4-5 mailbox
7. If a mailbox move fails in-between, will it be skipped and other mailbox moves in batch be attempted or they’ll be skipped?
8. If a mailbox move fails in-between, what will happen to source mailbox?, will that be intact and can be accessed by user as usual?
9. If a mailbox move fails in-between, the next attempt to move the same mailbox will be attempted from the point of failure OR from the scratch?
10. Can we use Exchange System Manager (Exchange 2003) console to move the mailboxes? (Reason why we would like to do this is that ESM allows scheduling the mailbox move)

Thanks

Taranjeet Singh

zamn