A new mandatory parameter, SourcePfPrimaryMailboxGuid, is being added to the New-MigrationBatch command for public folder migrations from Exchange 2013 (or later) on-premises to Exchange Online.
Why are we making this change?
Before this change, we relied on the on-premises server to find the primary public folder mailbox and route the Mailbox Replication Service (MRS) to the correct server. However, there were limitations with this method as the on-premises server relied on organization mailbox to proxy the call. In some cases, if the on-premises server routed the call to the wrong server, the migration batch could fail with MailboxDatabaseNotOnServerTransientException error.
With the introduction of this new parameter, we are eliminating the uncertainty involved in proxying of the MRS call. The change will ensure MRS will reach to the correct on-premises server hosting the primary public folder mailbox in all scenarios.
The change is specific to migration of public folder deployments on Exchange Server 2013 and above (public folder migrations from Exchange Server 2010 will continue to be same). Also, the change does not affect any on-going migration batches, only newly created migration batches will need to use this parameter.
Here’s an example of a new way of creating migration batch:
Step 1: Find out the GUID of primary hierarchy mailbox on-premises
On your on-premises Exchange server, open Exchange Management Shell and run the following command:
(Get-OrganizationConfig).RootPublicFolderMailbox.HierarchyMailboxGuid.GUID
Example:
[PS] C:\>(Get-OrganizationConfig).RootPublicFolderMailbox.HierarchyMailboxGuid.GUID
91edc6dd-478a-497c-8731-b0b793f5a986
Step 2: Create the migration batch
Open the EXO Management Shell and use the GUID from Step 1 to create the migration batch:
New-MigrationBatch -Name PublicFolderMigration -CSVData $bytes -SourceEndpoint $PfEndpoint.Identity -SourcePfPrimaryMailboxGuid 91edc6dd-478a-497c-8731-b0b793f5a986 -AutoStart
Please check the following documentation to find more details about the change:
The change is already being rolled out. If you receive following error when creating the migration batch, your tenant has already received the change:
"Source public folder PrimaryMailboxGuid is required for public folder migration."
Update 1/9/2020:
We have become aware of the issue that might cause some of our customers to get the following error when trying to execute the CMDlets once the change has been rolled out to their tenant:
The parameter 'SourcePfPrimaryMailboxGuid' cannot be found
If you have this problem, for immediate help, you can reach out to our support team, who will be able to help you resolve this. Alternatively, waiting for the changes to fully propagate is also possible (but this might take several days to happen on it's own).
Public Folder team
