Exchange Online Migration: Deprecation of BadItemLimit and use of Data Consistency Score
Hi All,
If you are a frequent Reader of the Exchange Team Blog, then you probably saw, that they announced to depreciate Bad Item Limit (BIL) and Large Item Limit (LIL) until end of 2022.
- Deprecating bad item limit and large item limit migration parameters
- Migrations with Data Consistency Score (DCS) & more than you ever wanted to know!
Let’s see that in Action
Connect-ExchangeOnline
$ONPREMCREDS = get-credential "CORP\Administrator"
Let’s create a MoveRequest with the BadItemLimit Parameter. You see there is a warning.
$Mailbox = "demo02@icewolf.ch"
New-MoveRequest -Identity $Mailbox -Remote -RemoteHostName mail.icewolf.ch -TargetDeliveryDomain icewolfch.mail.onmicrosoft.com -RemoteCredential $ONPREMCREDS -BadItemLimit 100
With the MoveRequestStatistics you can see that the DataConsistencyScore is not used
Get-MoveRequest -Identity Demo02@icewolf.ch | Get-MoveRequestStatistics | ft DisplayName, Status, StatusDetail, DataConsistensyScore, BadItemsEncountered, PercentComplete
New MoveRequest without the BadItemLimit or LargeItemLimit Parameter
$Mailbox = "demo04@icewolf.ch"
New-MoveRequest -Identity $Mailbox -Remote -RemoteHostName mail.icewolf.ch -TargetDeliveryDomain icewolfch.mail.onmicrosoft.com -RemoteCredential $ONPREMCREDS -BadItemLimit 100
Now the DataConsistencyScore is used
Get-MoveRequest -Identity Demo02@icewolf.ch | Get-MoveRequestStatistics | ft DisplayName, Status, StatusDetail, DataConsistensyScore, BadItemsEncountered, PercentComplete
DataConsistensyScore is “Perfect”
Let’s make some trouble: I’ve added MAPI Permissions with the Icewolf.Exchange.MAPI Module for demo06@icewolf.ch. And then i deleted the demo06 Account and waited until AAD connect has deleted the Account also in ExchangeOnline.
Add-MAPIPermission -Mailbox demo05@icewolf.ch -Trustee demo06@icewolf.ch -AccessRight Reviewer -Folder Inbox -IncludeSubfolders $true
Let’s create another MoveRequest to ExchangeOnline
$ONPREMCREDS = get-credential "CORP\Administrator"
$Mailbox = "demo05@icewolf.ch"
New-MoveRequest -Identity $Mailbox -Remote -RemoteHostName mail.icewolf.ch -TargetDeliveryDomain icewolfch.mail.onmicrosoft.com -RemoteCredential $ONPREMCREDS
As you can see the DataConsistensyScore is not “Perfect” but “Good”
Get-MoveRequest -Identity Demo05@icewolf.ch | Get-MoveRequestStatistics | ft DisplayName, Status, StatusDetail, DataConsistensyScore, BadItemsLimit, BadItemsEncountered, PercentComplete
Let’s find out what caused the DataConsistencyScore to change. It’s the seven Folders with MAPI Permissions where the User was deleted.
$MRS = Get-MoveRequestStatistics demo05@icewolf.ch -IncludeReport -DiagnosticInfo Verbose
$MRS.Report.Failures | group FailureType | fl
$MRS.report.Failures | foreach { $\_ | Select-Object @{name="index";expression={$i}},timestamp,failurecode,failuretype,failureside;$i++} | ft
If you need to Investigate and check - that’s the way to go.
As long the Mailbox has not completed you can always remove the Move Request (Remove-MoveRequest)
Often helps to Move the Mailbox in the Source to another Mailbox Database.
If that does not help try New-MailboxRepairRequest
If you find the Data Loss is Acceptable you can do that with the following Command (Sorry i was not able to create enough trouble to create a Screenshot)
Set-MoveRequest -Identity Demo05@icewolf.ch -SkippedItemApprovalTime $([DateTime]::UtcNow)
Set-MoveRequest -Identity Demo05@icewolf.ch | Resume-MoveRequest
Wish you all the best for your Exchange Migrations!
Regards
Andres Bohren
