SOLVED

Hyrbid Migration - 95% - Fails to Complete with error "TransientFailure"

Copper Contributor

Hello Everyone,

 

We are in the process of migrating mailboxes from On-Prem Exchange (2019) to EOL/M365.

 

Some brief server and environment details are:

 

1) 3 Exchange 2019 Servers housing Mailbox Databases in a DAG

2) 1 Exchange 2019 Server acting as the Hybrid Server (Static Nat on Firewall)

3) OnPrem Exchange Servers are located in the United States

4) EOL / O365 Tenant is located in JAPAN

 

The initial configuration steps, including the hybrid wizard, have been ran, without issue. We went through a brief "pilot" phase where we migrated about 30 mailboxes to EOL without issue, and this was about 3 weeks ago.

 

Yesterday, we were scheduled to begin out first Wave of production users with about 100 mailboxes in the Migration Batch. After about 8 hours, only 30 were completed, and the majority of the rest failed with the following error:

 

"Cannot enter finalization because Data Guarantee is lagging behind by more than 00:05:00. Failure: Database REDACTED-GUID doesn't satisfy the constraint SecondCopy because the commit time 7/27/2023 9:56:19 PM isn't guaranteed by replication time 7/27/2023 9:33:06 PM."

 

When searching for solutions to this error, many articles reference setting the "DataMoveReplicationConstraint" to "None" on the Database hosting the mailbox.

 

Set-MailboxDatabase <target mailbox database GUID> -DataMoveReplicationConstraint None

 

This appears to apply to OFFBOARDING only (O365 to OnPrem)...and NOT ONBOARDING (OnPrem to O365). Regardless, we set this parameter to None on all the OnPrem Databases and restarted the servers. Same behavior unfortunately.

 

After much troubleshooting we were unable to fix this issue. As next steps, we stopped and removed all Migration Batches and ensured that there were NO Move Requests currently pending. We then created a BRAND NEW user in Active Directory, and let it DirSync with Azure/EOL. We then populated the OnPrem mailbox with some emails and some calendar entries, and the total size of this mailbox was about 1 MB.

 

We then created a brand new migration batch which included this 1 mailbox. After about 15 minutes, the StatusDetail showed "WaitingForJobPickup".

 

When exporting the DiagnosticInfo to XML, we saw that same TransientFailure message at the bottom

 

Cannot enter finalization because Data Guarantee is lagging behind by more than 00:05:00. Failure: Database REDACTED-GUID doesn't satisfy the constraint SecondCopy because the commit time...

 

This is troubling because there is no way this new mailbox is corrupt or has excessive amounts of content / folders. It was the only account in the batch, and it was able to get to 95% before failing on the above message.

 

We are at a loss at the moment, and unable to get past this issue with completing the migration after 95%.

 

I have the XML Diagnostic Info / Debug, and can provide some additional logs if needed.

 

Does anyone know where we can potentially look for the root cause?

 

TIA!

 

 

 

 

2 Replies
Is replication of the mailbox databases in the on-premises DAG all healthy?
best response confirmed by MikeFisher (Copper Contributor)
1 best response

Accepted Solutions
best response confirmed by MikeFisher (Copper Contributor)