Self-Service Mailbox Migration in Exchange Online Dedicated · Client Access servers (if configured...
Transcript of Self-Service Mailbox Migration in Exchange Online Dedicated · Client Access servers (if configured...
Dedicated and ITAR-support Plans
Self-Service Mailbox Migration in Exchange Online Dedicated
Applies to: Office 365 Dedicated - Legacy 2013 Platform Release
Topic Last Modified: 31-Jan-2013
Topic Last Modified: Modifications Applied:
31-Jan-2013 Initial Release
Mailbox Migration is a self-service feature of the Exchange Online dedicated and ITAR-support plans of Office 365
for enterprises. The Exchange Admin Center (EAC) is used to initiate, manage, and monitor the movement of
mailboxes between on-premises environments and Exchange Online. Topic areas described within this self-service
migration guide are the following:
What is Self-Service Mailbox Migration? 4
Infrastructure Requirements 5
Hybrid Server 5
Network Connectivity 5
Active Directory Synchronization 5
Client Systems 6
Mailbox Migration to/from Exchange Online Dedicated 6
What do you need to know before you begin? 7
On-premises Exchange Server Configuration 7
On-Premises Permissions to Migrate Mailboxes 7
Exchange Online Dedicated Permissions to Migrate Mailboxes 8
Mailbox Preparation 8
Step 1: Create a migration endpoint 9
What do you need to know before you begin? 10
Create a migration endpoint for migrations in an Exchange hybrid deployment 10
How do you know this worked? 13
Step 2: Enable the MRS Proxy 13
Step 3: Create and execute migration batch to move mailboxes 13
Use EAC to manually select and move mailboxes 13
Use remote Windows PowerShell to manually select and move mailboxes 15
Use of a .csv input file for mailbox moves 15
Step 4: Remove completed migration batches 15
Step 5: Re-enable offline access for Outlook Web App 15
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How do you know this worked? 15
Manage Migration Batches in Exchange Online 17
Migration Dashboard 17
Overall migration statistics 18
Migration batches 19
Commands 20
Migration batch statistics 21
Migration Users Status Report 23
Migration users report 23
Columns in the list of migration users 24
Migration user statistics for a specific user 24
Migration phases 26
Migration Cmdlets 27
Appendix A – Factors that affect Exchange Online Dedicated migration performance 30
Overview of Exchange Online Dedicated email migration 30
Migration methods available with Exchange Online Dedicated 30
Summary of observed migration performance 31
Overview of Exchange Online email migration performance factors 31
Common migration performance factors 32
Network performance factors 33
Office 365 resource health-based throttling 34
Native Office 365 hybrid migration 34
Migration performance factors and best practices 34
Appendix B – Using a CSV File for Mailbox Migration 40
Supported attributes for CSV files for bulk moves or migrations 40
On-boarding remote move migrations in a hybrid deployment 41
Off-boarding remote move migrations in a hybrid deployment 42
Attribute values in the CSV file override the values for the migration batch 45
Appendix C – Mailbox migration in a multi-region environment 47
Preparation 47
Execution 48
Verification 48
Troubleshooting 49
Self-Service Migration in Exchange Online Dedicated
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Important
1. Preview material may be updated periodically before becoming a published version within the
Exchange Online Dedicated area of the Microsoft TechNet Library. Rather than downloading or
printing the content, viewing the material at this site is recommended whenever reference
information is needed.
2. Not all generally available documentation produced by Microsoft to describe the features and
functionality of Exchange 2013 is applicable to the dedicated and ITAR-support plan offerings of
Office 365 for enterprises. Content accessible via links provided in this content are reliable sources.
3. Unless otherwise stated, all references to “dedicated plans” or “Exchange Online Dedicated” also
apply to the International Traffic in Arms Regulations (ITAR-support) version of Exchange Online.
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What is Self-Service Mailbox Migration? The process to migrate mailboxes between an on-premises environment and Exchange Online Dedicated involves
establishing the required infrastructure, applying required Active Directory updates for the user objects representing
each mailbox, and using specific tools to execute the migration.
When an Exchange hybrid deployment has been established to bridge the on-premises and online Exchange
organizations, user mailbox data then can be migrated from an on-premises Exchange 2013, Exchange 2010, Exchange
2007, or Exchange 2003 mail server to Exchange Online Dedicated. The movement of mailboxes aligns with the
following processes:
On-boarding remote move migration: Allows mailboxes from an on-premises Exchange organization or
the multi-tenant version of Exchange Online to be moved to Exchange Online Dedicated. The process is also
known as an on-boarding remote move migration because you onboard mailboxes to Exchange Online.
Off-boarding remote move migration: Allows mailboxes from an Exchange Online Dedicated
organization to be migrated to an on-premises Exchange Server or to the multi-tenant version of Exchange
Online. The process is known as off-boarding.
Notes
1. Both on-boarding and off-boarding remote move migrations involving an on-premises
Exchange organization are initiated from your Exchange Online organization. If the off-
boarding source or on-boarding target is the multi-tenant version of Exchange Online, the
EAC migration tool must be launched from within the multi-tenant environment and the
required Migration Endpoint (Exchange Online Dedicated) must be indicated and or created.
2. Only mailbox-enabled users within the on-premises Exchange or Exchange Online Dedicated
environment can be migrated.
3. To migrate mailboxes from an on-premises environment to multiple geographic regions
supported by Exchange Online Dedicated, the Exchange CustomAttribute for each on-
premises mailbox user (a.k.a. the Extension Attribute of a user object held in Active Directory)
must be set. See the SetMailboxType section of the Office 365 Dedicated and ITAR-support
Plans Provisioning Tools Handbook held within the Customer Extranet site for additional
information. Once the attribute has been set, the migration feature will automatically route
the mailbox to the correct region.
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Infrastructure Requirements
Hybrid Server
The initial on-boarding of user mailbox data requires the use of a separate on-premises Exchange Server referred to
as a hybrid server to bridge the on-premises and online Exchange organizations. A hybrid server can be used to
support just the migration of mailboxes during the migration period or it can be used in a long term coexistence
configuration to support migrations as well as the presentation of calendar free/busy availability and calendar
sharing between the on-premises and online organizations.
The requirements for the hybrid server are described in Exchange Server 2013 Hybrid Deployment for Exchange
Online Dedicated. After a hybrid configuration has been chosen and implemented, specific processes must be
followed and specific tools must be used to perform the mailbox migrations.
Network Connectivity
You must verify that network connectivity exists between the Exchange Online Dedicated organization and your on-
premises Exchange organization. Connectivity can be via the dedicated networking facilities between Exchange
Online Dedicated and your on-premises systems, via the Internet, or a combination of both.
Active Directory Synchronization
The Microsoft Managed Solutions Services Provisioning Provider tool (MMSSPP – commonly referred to as
“Mississippi”) is used to propagate on-premises Active Directory object data to the Active Directory of Office 365
Dedicated. To support an on-boarding migration of your on-premises mailboxes to Exchange Online Dedicated, a
corresponding object must exist in the Active Directory of Office 365 Dedicated. For additional information
describing how provisioning is implemented within Office 365 Dedicated, how MMSSPP functions, and how to
initially configure your on-premises Active Directory for MMSSPP synchronization, see the MMSSPP & Provisioning
Tools landing page within the Customer Extranet site to access the links to the MMSSPP Customer Deployment
Guide, MMSSPP Identity Synchronization Handbook, and the Office 365 Dedicated and ITAR-support Plans
Provisioning Tools Handbook.
Note
If MMSSPP must synchronize any user objects that have mailboxes in Exchange environments that
are hosted in other Active Directory forests (i.e., not the primary forest being used for the MMSSPP
synchronization), these objects must have all of their Exchange service specific settings (e.g.,
PublicDelegates, msExchRequireAuthToSendTo, authoring, etc.) copied to the Active
Directory object in the forest from which MMSSPP synchronizes. See Appendix B of the MMSSPP
Identity Synchronization Handbook for a complete list of the attributes by object type that are
currently supported for synchronization by MMSSPP.
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To gain an understanding of the object attributes you will need to populate in your on-premises Active Directory to
support an off-boarding migration, see the attribute listings shown in Prepare Mailboxes for Cross-Forest Move
Requests. If a large scale on-boarding or off-boarding if mailboxes is required due to a corporate divestiture,
merger, or acquisition, contact your Service Delivery Manager for additional guidance.
Client Systems
Prior to the start of the migration, all client systems must be confirmed to be compliant for use with Exchange
Online. See the client system software requirements description of the Client and Application Connectivity section of
the Exchange Online Dedicated Service Description.
Mailbox Migration to/from Exchange Online Dedicated Within Exchange Online Dedicated, individual or multiple mailboxes can be migrated using the Exchange Admin Center
(EAC) or remote Windows PowerShell. Exchange Online Dedicated is used to manage mailbox migration in either
direction between the on-premises and online environments via the hybrid Exchange server within in your on-premises
environment. As described in the Infrastructure Requirements section above, you must have an Exchange hybrid
server deployed to use the remote move migration method for migrations to/from the on-premises
environment. Mailbox migration between the multi-tenant and dedicated versions of Exchange Online does not
require the use of a hybrid server.
The remote move migration method is used to migrate mailboxes via an on-premises Exchange hybrid server. The
execution of mailbox migrations is invoked as a batch. The batch can be created by manually selecting one or more
mailboxes from the source forest or by preparing a Comma Separated Values (.csv) file that lists the mailboxes to be
migrate. The .csv file can be uploaded into EAC or used by the New-MigrationBatch cmdlet from within remote
Windows PowerShell.
Notes
1. Both on-boarding and off-boarding remote move migrations involving an on-premises Exchange
organization are initiated from your Exchange Online organization. If the off-boarding source or on-
boarding target is the multi-tenant version of Exchange Online, the migration must be launched from
within the multi-tenant environment, the required Migration Endpoint (Exchange Online Dedicated) must
be created, and this endpoint must be referenced when invoking the migration. Other configuration steps
also must be addressed to initiate a migration involving the multi-tenant version of Exchange Online –
contact your Service Delivery Manager for assistance.
2. If a user has an archive mailbox either as an element of a standard active mailbox account or while on
Legal Hold, both the primary and archive mailboxes will be migrated.
3. For a configuration involving the presence of Lotus Domino mailboxes on-premises, see the Planning,
Deployment, and Migration section of the Exchange Online Dedicated Service Description for a description
of migration services offered for this mailbox type.
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What do you need to know before you begin?
In addition to the infrastructure requirements described above, the collection of requirements included below must
be met prior to the start of mailbox migrations.
On-premises Exchange Server Configuration
The mailbox Replication Service Proxy (MRS Proxy) must be enabled on your on-premises Exchange 2010/2013
Client Access servers (if configured to fulfill the hybrid server role) or on your standalone hybrid Exchange server if
your on-premises mail server is Exchange 2003/2007. Also, the Exchange 2010/2013 Client Access server of your
hybrid deployment must be configured to send and receive network traffic on Port 443 from the 141.251.0.0/16
subnet (mailbox migration data will be transferred between Exchange Online Dedicated and the customer
environment on Port 443).
On-Premises Permissions to Migrate Mailboxes
When you migrate on-premises Exchange mailboxes to and from Exchange Online Dedicated, the on-premises
account that you use to connect to your on-premises Exchange organization during the migration must have the
necessary permissions to access, and in some cases modify, the on-premises mailboxes that you want to migrate.
The account, referred to as the migration administrator, is used to create a migration endpoint for your on-
premises organization. To successfully create a migration endpoint (or to create a migration batch if no migration
endpoints exist in your Exchange Online organization), the migration administrator account must align with at least
one of the following permission options within your on-premises Exchange organization:
The migration administrator must be a member of the Domain Admins administrative group in Active
Directory in the on-premises organization; or
The migration administrator must be a member of the Exchange Recipients Administrators admistrative
group in Active Directory in the on-premises organization AND be a Local Administrator on all Client Access
Servers that will be used as migration MRS Proxy endpoints; or
If you have an on-premises Exchange 2010 and Exchange 2013 organization, the migration administrator
must be a member of the Organization Management or Recipient Management built-in role group (the
default roles associated with the built-in role groups and the original exposed cmdlets/parameters for these
groups are assumed to exist) AND be a Local Administrator on all Client Access servers that will be used as
migration MRS Proxy endpoints.
You can use the Exchange Management Shell in your on-premises organization to assign the necessary
permissions to migrate mailboxes to Exchange Online.
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Notes
Since Exchange Server 2003 does not support the Exchange Management Shell, you have to use the Active
Directory Users and Computers view to grant Full Access permission and also use Exchange Server
Manager to assign the Receive As permission. For more information, see the following:
How to assign users or groups full access to other user mailboxes
How to assign service account access to all mailboxes in Exchange Server 2003
Exchange Online Dedicated Permissions to Migrate Mailboxes
In addition to establishing appropriate access to the on-premises Exchange environment, you need to be a
member of the Mailbox Migrations role group within Exchange Online Dedicated. A self-service administration
account is used to initiate and manage cross-forest remote move migrations to Exchange Online. See the Self-
Service Administration content within the Exchange 2013 Platform Readiness area of the Customer Extranet site
for additional information.
Mailbox Preparation
The size of a mailbox and available network bandwidth are limiting factors in achieving a high migration velocity. A
common practice to reduce the size of the mailbox is to move email items out of the mailbox to an archive (e.g., a
.PST file) either manually or with auto-archive functionality. To reduce mailbox size, the following actions are
recommended:
Delete or archive mail in the Sent Items folder.
Delete or archive all Calendar attachments.
Delete or archive Calendar items over 30 days old.
Delete or archive Inbox items over 90 days old.
Search for and delete attachments over 5 MB.
Disable Journaling.
Empty the Deleted Items folder.
Run the Mailbox Cleanup wizard from the Outlook Tools menu (Outlook only).
Notes
1. If the mailbox owner moves the mail items back to the new Exchange Online mailbox after migration,
the Exchange Online mailbox will not allow the user to reply to these mail items.
2. The day span and file sizes described in the bullet list above are recommendations only; these values
may not be suitable for your organization.
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Your organization will need to assess the number of mailboxes, size of each mailbox, and the rate of mailbox size
growth in your existing environment. The information obtained will help you evaluate the impact of migration traffic
on your network. If your organization enforces maximum mailbox size limits, this information also is important to
consider when you define Exchange Online storage capacities. Your new Exchange Online environment should let all
users store the same amount of data allowed for their mailbox and also be size to accommodate growth. You
should also confirm if the capacities of your Exchange Online plan(s) support your existing mailbox inventory. Each
Exchange Online Dedicated plan supports a specific mailbox storage level. For more information, see the Standard
Messaging Plan Mailboxes description of the Mailbox Features section of the Exchange Online Dedicated Service
Description.
For additional recommendations to streamline the migration process, see Appendix A – Factors that affect Exchange
Online Dedicated migration performance. If assistance is required to support any level of migration planning and
preparation, contact your Service Delivery Manager to gain access to additional Microsoft resources.
Step 1: Create a migration endpoint
A migration endpoint is a management object that contains the connection settings and administrator credentials
for your on-premises environment. The migration endpoint also defines the number of mailboxes to migrate
simultaneously during initial synchronization and the number of mailboxes to synchronize simultaneously during
incremental synchronization (occurrence once every 24 hours for selected migration types). During incremental
synchronization, on-premises and Exchange Online mailboxes are synchronized so that new email sent to mailboxes
on the source server is copied to the corresponding Exchange Online mailbox.
Prior to the execution of a remote move migration to on-board or off-board mailboxes in an Exchange hybrid
deployment, an Exchange remote migration endpoint must be created. Consider the following:
Recommended is the creation of the migration endpoint in advance followed by selection of the endpoint
when the migration batch is created (Step #3 below).
If no endpoints exist at the time a migration batch is created, you can provide server and remote credentials
when prompted during the batch creation step.
If one or more endpoints have been configured but the endpoint you require is not present in the list of
available endpoints displayed at the time the migration batch is created, you must follow the Use the EAC to
create an Exchange remote migration endpoint instructions below to add your entry to the endpoint
selection list.
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What do you need to know before you begin?
Estimated time to complete each procedure: 3 minutes.
You need to be assigned permissions before you can perform this procedure or procedures. To see what
permissions you need, see the Mailbox Move and Migration Permissions section in the Recipients
Permissions topic.
When you create a migration endpoint, by default, it will support 20 maximum concurrent migrations during
initial synchronization and a maximum of 10 concurrent incremental synchronizations. You can specify a
different number of concurrent migrations when you create a migration endpoint. To change these settings,
you can edit an existing migration endpoint using the EAC or the Set-MigrationEndpoint cmdlet.
There is a limit of 100 concurrent migrations.
We recommend that you test the connection settings to the server that hosts the mailboxes that you want
to migrate. The connection settings will be tested when you create a migration endpoint; verifying the
settings before you create an endpoint will give you an opportunity to troubleshoot any issues. Run the
following commands using remote Windows PowerShell within Exchange Online Dedicated to test the
connection settings to the source server:
$Credentials = Get-Credential
Test-MigrationServerAvailability –ExchangeRemoteMove –Autodiscover –EmailAddress <email address
for on-premises administrator account> -Credentials $Credentials
For information about keyboard shortcuts that may apply to the procedures in this topic, see Keyboard
Shortcuts in the Exchange Admin Center.
Create a migration endpoint for migrations in an Exchange hybrid deployment
The migration endpoint contains the connection settings for a Client Access server in your on-premises
Exchange organization.
Note
The same Exchange remote migration endpoint can be used for moving on-premises mailboxes to
Exchange Online or for moving Exchange Online mailboxes to your on-premises organization
Important
You must have a hybrid deployment configured between your on-premises and Exchange Online
organizations to create an Exchange remote migration endpoint and to use remote move migrations to
move mailboxes between your on-premises and Exchange Online organizations. For more information
regarding hybrid deployments, review the Infrastructure Requirements section above.
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Use the EAC to create an Exchange remote migration endpoint
1. In the EAC of Exchange Online Dedicated, navigate to Recipients > Migration.
2. Click (more) on the EAC toolbar and select Migration endpoints in the pop-up that appears.
3. On the Migration endpoints page, click (add).
4. On the Enter on-premises account credentials page, complete the following boxes:
Email address Type the email address of any user in the on-premises Exchange organization that will
be migrated using this endpoint. Exchange Online will test the connectivity to this user's mailbox.
Account with privileges Type the user name (using the domain\user name format or email address)
for an account that has the necessary administrative privileges in the on-premises organization.
Exchange Online will use the Autodiscover service and this account to detect the migration endpoint
and to test the permissions assigned to this account by accessing the mailbox specified in the previous
box.
Password of account with privileges Type the password for the administrator account that you
specified in the previous box.
5. Click Next. Exchange Online uses the information provided to test connectivity to an on-premises server
and then displays the Confirm the migration endpoint page. Do one of the following based on whether
the connection settings were successfully detected:
o If Exchange Online successfully connects to an on-premises server, the connection settings are
displayed. Click Next.
o If the test connection to an on-premises server isn't successful, you have to enter the fully qualified
domain name (FQDN) of the on-premises server that the MRS Proxy service is running on in your
hybrid deployment (e.g., mail.contoso.com). The MRS Proxy service typically runs on the Exchange
Client Access server in your on-premises organization. You have to successfully connect to an on-
premises server to continue.
Important
Online creates a new migration endpoint using the connection settings that were successfully
discovered or that you provided manually. We recommend that you create migration endpoints whose
connection settings were automatically discovered rather than creating endpoints whose settings you
entered manually. This is because the Autodiscover service will be used to connect to each user mailbox
during the migration. If manual settings are used, Exchange Online won't use the Autodiscover service,
but will connect to a specific source server using the connection settings you manually entered. If you
use manual settings and have multiple on-premises Exchange servers, you may need to create different
migration endpoints that correspond to each server.
7. Click Next. Enter information in the following boxes:
Migration endpoint name - Name displayed in the list of migration endpoints. It's also used in the
drop-down list of migration endpoints when you select a migration endpoint while creating a
migration batch. This is required.
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Maximum concurrent migrations - Number of connections to the source server that are available to
migrate on-premises mailboxes and mailbox items to Exchange Online during initial and incremental
synchronization. If the value is set to 20, which is the default value, you can migrate up to 20 mailboxes
at the same time.
If multiple migration batches use the same Exchange remote migration endpoint, the maximum
number of concurrent migrations allowed by the migration endpoint is shared across all the migration
batches.
Note
As previously stated, there is a limit of 100 concurrent migrations for all
Exchange remote migration endpoints in your organization.
Maximum concurrent incremental syncs - Number of connections to the source server that are
available to perform incremental synchronizations. If the value is set to 10, the default value, then
incremental synchronization can be performed on up to 10 mailboxes at the same time.
For example, if the endpoint is configured with 100 maximum concurrent migrations and 40 maximum
concurrent incremental syncs, 40 connections can be used for incremental synchronization, if
necessary. The other 60 connections are reserved for initial synchronizations.
8. Click New to create the migration endpoint.
Use the Shell to create an Exchange remote migration endpoint
This example creates a migration endpoint that can be used to support either on-boarding or off-boarding for
remote move migrations. In both cases, the migration endpoint is an Exchange server in your on-premises
Exchange organization that is running the MRS Proxy service – typically the Client Access server. Using remote
Windows PowerShell in your Exchange Online Dedicated environment, execute the steps below.
Note
You must be a member of the Mailbox Migration role group within Exchange Online
Dedicated to execute the New-MigrationEndpoint cmdlet shown below.
$Credentials = Get-Credential
New-MigrationEndpoint –ExchangeRemoteMove –Name OnpremEndpoint -Autodiscover –EmailAddress <email
address for on-premises administrator account> -Credentials $Credentials
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How do you know this worked?
To verify that you've successfully created an Exchange remote migration endpoint, do one of the following:
1. In the EAC, navigate to Recipients > Migration.
2. Click (more) on the EAC toolbar and select Migration endpoints in the pop-up that appears. The
new migration endpoint is displayed in the list, and the endpoint type is Exchange Remote. Alternatively, use
remote Windows PowerShell to run the following command to display information about the migration
endpoint:
Get-MigrationEndpoint <identity> | Format-List EndpointType,RemoteServer,UseAutoDiscover,Max*
Step 2: Enable the MRS Proxy
To allow the on-premises Client Access server to accept incoming remote move requests, you have to enable the
MRS Proxy endpoint. If the MRS Proxy is not already enabled, follow these steps in the EAC:
1. Within the on-premises Exchange organization, open the EAC and navigate to Servers > Virtual
Directories.
2. Select the Client Access server, select the EWS virtual directory, and click Edit.
3. Select the MRS Proxy enabled check box and then click Save.
See Enable the MRS Proxy Endpoint for Remote Moves for additional information including Windows PowerShell
examples.
Step 3: Create and execute migration batch to move mailboxes
You can use the migration dashboard of the EAC or remote Windows PowerShell in Exchange Online Dedicated to
either move existing user mailboxes in the on-premises organization to the Exchange Online organization or to
move Exchange Online mailboxes to the on-premises organization. A Comma Separated Values (.csv) file containing
all mailboxes to be migrated also can be used as input for the EAC or PowerShell options.
Use EAC to manually select and move mailboxes
Within Exchange Online Dedicated, perform the following:
1. Open the EAC and then navigate to Office 365 Dedicated > Recipients > Migration.
2. Click + (add) and then select either of the following:
Migrate to Exchange Online
Migrate from Exchange Online
3. On the Select the users page, click + (add), select the on-premises users to move to Office 365, click +
(add), and then click OK. Click Next.
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4. If moving on-premises mailboxes to Exchange Online Dedicated and migration endpoints have not been
created, the Enter the Windows user account credential page will appear. Enter the on-premises
administrator account name in the On-premises administrator name text field and enter the associated
password for this account in the On-premises administrator password text field. For example,
“corp\administrator” and a password. Click Next.
Note
If you’ve already created a migration endpoint, you’ll receive an endpoint confirmation
prompt for this step. If you’ve created two or more migration endpoints, you must choose
an endpoint from the migration endpoint drop-down menu.
5. On the Confirm the migration endpoint page, verify that the FDQN of your on-premises Client Access
server is listed when the dashboard shows a confirmation of the migration endpoint. For example,
“mail.contoso.com”. Click Next.
Note
The MRS Proxy service on the Exchange Client Access servers automatically throttles the
mailbox move requests when you select multiple mailboxes to move to Exchange Online.
The total time to complete the mailbox move depends on the total number of mailboxes
selected, the size of the mailboxes, and the configuration of the MRS Proxy.
6. On the Move configuration page, enter a name for the migration batch in the New migration batch
name text field. Use the down arrow to select the Target delivery domain for the mailboxes that are
migrating to Office 365 Dedicated. In most hybrid deployments, this is the coexistence SMTP domain
used for Exchange Online organization mailboxes. For example, mgd.contoso.com. To apply specific
migration settings for BadItemLimit and LargeItemLimit, select More Options… in this view. Descriptions of
the limit options can be found in the Parameters section of the New-MigrationBatch cmdlet description
(custom cmdlet version specifically for Exchange Online Dedicated – see Migration Cmdlets below). Click
Next.
7. On the Start the batch page, select at least one recipient to receive the batch complete report. Also select
appropriate batch start and complete options. Select Automatically start the batch and Automatically
complete the migration batch options if custom settings are not required. If start/complete options are
required, see the New-MigrationBatch cmdlet description (custom version specifically for Exchange Online
Dedicated) in the Migration Cmdlets section below. After all start/complete settings have been applied, click
New.
Note
If you must migrate an Inactive mailbox, the mailbox first must be re-enabled as an active mailbox type,
migrated, and then placed back into an inactive status on the destination system.
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Use remote Windows PowerShell to manually select and move mailboxes
To use remote Windows PowerShell to execute a remote move migration, see the New-MigrationBatch cmdlet
description (custom version specifically for Exchange Online Dedicated) in the Migration Cmdlets section below.
Use of a .csv input file for mailbox moves
You can use a CSV file to bulk migrate a large number of user mailboxes. You can specify a CSV file when you use
the Exchange Admin Center (EAC) or remote Windows PowerShell to create a migration batch. For additional
information, see Appendix B - Using a CSV File for Mailbox Migration.
Step 4: Remove completed migration batches
After your mailbox moves have completed, we recommend the completed migration batches to minimize the
likelihood of errors if the same users are moved again. To remove a completed migration batch:
1. Open the EAC and navigate to Office 365 Dedicated > Recipients > Migrations.
2. Click a completed migration batch, and then click Delete.
3. On the deletion warning confirmation dialog, click Save.
Step 5: Re-enable offline access for Outlook Web App
Offline access in Outlook Web App lets users access their mailbox when they are not connected to a network. The
default Client Access server configuration of Exchange Online Dedicated enables Outlook Web App offline access. If
the feature was enabled for supported Web browsers using group policy settings within the on-premises
environment prior to the migration of mailboxes, the offline access feature will be active following migration to
Exchange Online Dedicated. See Offline access in Outlook Web App 2013 for a description of the offline access
feature including use of the Set-OwaMailboxPolicy cmdlet to enable/disable the feature (an exposed remote
Windows PowerShell cmdlet within Exchange Online Dedicated). See Using Outlook Web App offline for a user level
description of the feature.
How do you know this worked?
You can verify the status of the migration batch by opening the EAC and selecting Office 365 Dedicated >
Recipients > Migration. You can also run the following remote Windows PowerShell cmdlet to verify the status of
the migration batch:
Get-MigrationBatch –Identity <batch name>
Within the EAC, the move status for specific mailboxes within the batch can be viewed by selecting Recipients >
Migration. The Status value is Syncing during the mailbox move and it is Completed when the mailbox has
successfully migrated.
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When the Status entry for the migrated mailbox is Completed, you can verify the result by examining the
properties of the mailbox. For an on-boarding migration, access the EAC of Exchange Online Dedicated, navigate to
the Recipients area, and select the tab that represents the type of mailbox that was migrated, i.e., User for a
standard or shared mailbox or Resource for a resource mailbox. The mailbox should show a Mailbox Type of
Linked. If Exchange Server 2013 is the on-premises version of Exchange to receive off-boarded mailboxes, the
mailbox value type displayed in the on-premises EAC will be User. For either environment, the Windows PowerShell
cmdlet Get-Mailbox can be used to check mailbox status.
Mailbox Type Destination
Exchange Environment
EAC Navigation
in Destination Environment
Mailbox Type Value
Displayed
User Online Recipients > Mailboxes Linked
User On-premises Recipients > Mailboxes User
Resource Online Recipients > Resource Room or Equipment
Resource On-premises Recipients > Resource Room or Equipment
Shared Online Recipients > Mailboxes1 Linked
Shared On-premises Recipients > Mailboxes1 User
1Exchange Online Dedicated does not use the RecipientType and RecipientTypeDetails properties of Exchange Server to
identify shared mailboxes; thus, the shared tab of the EAC is not applicable. A shared mailbox is represented as a user
mailbox within Exchange Online Dedicated. The provisioning attribute for the object that represents a shared mailbox must
be set to include TYPE=SHARED. See the Office 365 Dedicated and ITAR-support Plans Provisioning Handbook for additional
information.
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Manage Migration Batches in Exchange Online You can use the Migration dashboard in the Exchange Admin Center (EAC) to manage mailbox migrations to
Exchange Online Dedicated. The Migration dashboard displays statistics about the overall migration in addition to
statistics about a specific migration batch. You can create, start, stop, pause, and edit migration batches.
Migration Dashboard
To access the Migration dashboard in the EAC, select Recipients > Migration. The following screenshot identifies
the different areas of the Migration dashboard that you can use to get migration information and manage
migration batches.
Included below are descriptions of the five sections highlighted in the EAC migration Tab view shown above.
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Overall migration statistics
Click Status for all batches to display the overall statistics about all migration batches that have been created. The
following fields display cumulative information about all migration batches.
Field Description
Total mailboxes The total number of mailboxes from all current migration batches.
Synced mailboxes The number of mailboxes from all migration batches that were
successfully migrated.
Finalized mailboxes The number of mailboxes from all migration batches that have been
finalized. Finalization only occurs when using remote move
migrations to migrate mailboxes between your on-premises
Exchange organization and Exchange Online in an Exchange hybrid
deployment. Mailboxes can be finalized after the initial
synchronization is successfully completed. For more information
about finalizations in remote move migrations, see Complete-
MigrationBatch.
Failed mailboxes The number of mailboxes from all migration batches for which
migration failed.
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Migration batches
Migration batches that are created are listed in the migration queue. The following columns display information
about each migration batch.
Column Description
Name The name of the migration batch that was defined when the migration batch was
created.
Status The status of the migration batch. The following is a list of the different status
states for migration batches, along with what you can do with migration batches in
each of these states:
Created: The migration batch has been created, but it hasn't been started. In
this state, you can start, edit, or delete it.
Syncing: The migration batch has been started, and mailboxes in the migration
batch are being actively migrated. When a migration batch is in this state, you
can stop it.
Stopped: The migration batch is stopped, and no more mailboxes from the
batch are being migrated. When a migration batch is in this state, you can
restart it.
Synced: The migration batch has completed, and no mailboxes are being
actively migrated. A migration batch in this state may contain errors if
mailboxes weren’t migrated.
Synced with errors: The migration batch has completed, but some mailboxes
failed migration. Mailboxes that were successfully migrated in migration
batches with errors are still synchronized every 24 hours during incremental
synchronization.
Total Indicates the number of mailboxes in the migration batch.
Synced Indicates the number of mailboxes that were successfully migrated.
Finalized The number of mailboxes in the migration batch that have been finalized.
Finalization is only performed for migration batches for remote move migrations in
an Exchange hybrid deployment. For more information about the finalization
process, see Complete-MigrationBatch.
Failed The number of mailboxes in the migration batch for which migration failed. You
can display information about specific mailboxes that have migration errors. For
more information, see Migration Users Status Report.
Important
Migration batches with a status of Synced that have no administrator-initiated activity for
the last 90 days (for example, no administrator has stopped and restarted a migration batch
or edited a migration batch) will be stopped and then deleted 30 days later if no further
action is taken by the administrator.
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Commands
The Migration dashboard contains a set of commands that you can use to manage migration batches. After you
create a migration batch, you can select it and then click one of the following commands. If a migration batch is in
a status state that isn’t supported by a command, the command is either dimmed or not displayed because it’s
unavailable.
Command Description
New Create a new migration batch. Use this command to migrate on-
premises mailboxes to Exchange Online (also called on-boarding) or
to migrate Exchange Online mailboxes back to your on-premises
Exchange organization in a hybrid deployment.
Edit Edit an existing migration batch. You can change the migration
endpoint used for the migration batch. You can only edit a
migration batch that has a status of Created.
Start Start a migration batch that’s been created. After the batch is
started, the status is changed to Syncing.
Resume Resume the running of a migration batch that was paused and has
a status of Stopped. If there are errors for a migration batch, you
can restart it with this command and Exchange Online will attempt
to migrate the mailboxes that failed.
Pause Stop a migration batch that’s currently running or that’s been
started but has a status of Queued. You can resume incremental
synchronizations by selecting the migration batch and clicking
Resume.
Delete Delete a migration batch after you verify that all mailboxes in the
migration batch have been successfully migrated and that mail is
being routed directly to cloud-based mailboxes after you’ve
configured your MX record to point to Office 365. When you delete
a migration batch, Exchange Online cleans up any records related
to the migration batch and removes it from the list.
More Click this command and then click Migration endpoints to create
new migration endpoints or view and edit existing migration
endpoints. For more information, see Create Migration Endpoints.
Refresh Refresh the Migration dashboard to update the information
displayed for the overall migration statistics, the list of migration
batches, and the statistics for the selected migration batch.
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Migration batch statistics
The details pane in the Migration dashboard displays the following information about the selected migration batch.
Overall Status
Field Description
Type Indicates the migration type of the selected migration batch. The
value of this field also denotes the type of migration endpoint
associated with the migration batch.
Remote move migration: The migration batch is either an on-
boarding or off-boarding remote move migration in an
Exchange hybrid deployment.
Direction Indicates if mailboxes are being migrated to Exchange Online or to
your on-premises Exchange organization.
On-boarding indicates that mailboxes are being migrated to
Exchange Online. The supported on-boarding migration type
for Exchange Online Dedicated is remote move migrations.
Off-boarding indicates that Exchange Online mailboxes are
being migrated to your on-premises Exchange organization.
Off-boarding remote move migrations are the only type of off-
boarding migration.
Status The current state of the selected migration batch.
Created
Syncing
Stopped
Synced
Synced with errors
See the previous description of each of these states.
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Mailbox Status
Synced mailboxes The number of mailboxes out of the total number in the migration
batch that have successfully completed initial synchronization. This
field is updated during the migration.
Finalized The number of mailboxes out of the total number in the migration
batch that have successfully been finalized. Finalization only occurs
in on-boarding and off-boarding remote move migrations.
Failed mailboxes The number of mailboxes that failed initial synchronization.
View details Click View details to display status information for each mailbox in
the migration batch. For more information, see Migration Users
Status Report.
Statistics
Field Description
Created by The email address of the Exchange Online administrator who
created the migration batch.
Create time The date and time when the migration batch was created.
Start time The date and time when the migration batch was started. For
batches scheduled with the StartAfter time/date variable set, the
Start time will display as $null as this reflects the time the batch was
initially submitted.
Initial sync time The date and time when the migration batch completed initial
synchronization.
Initial sync duration The amount of time it took to complete the initial synchronization
for all mailboxes in the migration batch.
Last sync time The last time the migration batch was restarted or the last time that
incremental synchronization was performed for the batch.
Associated endpoint The name of the migration endpoint being used by the migration
batch. You can click View details to view the migration endpoint
settings. You can also edit the settings if none of the migration
batches using the endpoint are currently running.
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Migration Users Status Report You can use the Migration dashboard in the Exchange Administration Center (EAC) to display migration status
information for all mailboxes in a migration batch. You can also display detailed migration information for each user
in a migration batch. This information, also called migration user statistics, can help you troubleshoot issues that
might prevent the migration of a user’s mailbox or mailbox items. You can display this migration status information
for migration batches that are currently running, that have been stopped, or that are complete.
Migration users report
To access the migration users report for a migration batch, select Recipients > Migration, select the migration
batch, and then click View details under Mailbox status in the details pane.
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The name of the migration batch and the following commands are displayed at the top of the window.
Command Description
Delete Delete the selected user from the list of migration users.
Refresh Refresh the list of migration users to update the information
displayed for the users in the migration batch.
Columns in the list of migration users
Column Description
Email Address The user’s email address.
Status The user’s migration status. See the status descriptions in the table
in the next section.
Items Synced The number of items in the user’s on-premises mailbox that were
successfully migrated to the Exchange Online mailbox.
Items Skipped The number of items in the user’s on-premises mailbox that weren’t
migrated to the Exchange Online mailbox.
Migration user statistics for a specific user
To view status information (also called migration user statistics) for a specific mailbox, mail contact, or distribution
group, click the mailbox, contact, or distribution group in the list. Status information for the selected mail object is
displayed in the details pane. The following table describes each field displayed in the details pane.
Field Description
Status Identifies the specific point in the migration process for each mail
object in the migration batch. This status is more specific than the
high-level status summary displayed in the list of migration users.
The following list describes each status state.
Queued The object is in a migration batch that is running, but
the migration of the object hasn’t started yet. Objects typically
have a status of Queued when all of the connections in the
migration endpoint associated with the migration batch are
being used.
Provisioning The migration process has started for the mail
object, but it isn’t provisioned yet.
Provision updating The mail object has been provisioned, but
not all of the object’s properties were migrated. For example,
after a distribution group has been migrated, this state occurs
when members of the group haven’t been migrated yet or
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Field Description
there’s a problem migrating a user who is a member of the
group. In this case, the status indicates the migration process
can’t update the group membership because not all group
members have been migrated.
Synced The migration process successfully provisioned the
Exchange Online mailbox and completed the initial
synchronization where all mailbox items were copied to the
cloud-based mailbox. For cutover Exchange migrations and
IMAP migrations, this status can also indicate that incremental
synchronization completed successfully.
Failed The provisioning or the initial synchronization of the
mail object failed. If an Exchange Online mailbox is successfully
created for a user, but the migration of mailbox items fails, the
status for the user will be Failed.
Skipped item details Click Skipped item details to display information about each item
that was skipped for the selected user. The following information
about each skipped item is displayed:
Date The time stamp of the mailbox item.
Subject The subject line of the message.
Kind The type of error that caused the item to be skipped.
Folder name The folder where the skipped item is located.
Data migrated The total amount of data (in bytes and megabytes) for the mailbox
items that have been migrated to the Exchange Online mailbox.
This number includes items migrated in both the initial and
incremental synchronizations. This field doesn't have a value for
IMAP migrations.
Migration rate The average transfer rate (in bytes or MB per minute) of data
copied to the Exchange Online mailbox. This field doesn't have a
value for IMAP migrations.
Error If the migration for the user failed, this field displays a description
of the error. This error description is also included in the Migration
Errors report.
Report Click Download the report for this user to open or save a detailed
migration report that contains diagnostic information about the
migration status of the user. You or Microsoft Support can use the
information in this report to troubleshoot failed migrations.
Last successful sync date The last time that any new items in the on-premises mailbox were
copied to the cloud-based mailbox.
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Click More details to display the following additional information about the selected migration user.
Field Description
Queued duration The length of time the user had a status of Queued.
In-progress duration The length of time the user was actively being migrated.
Synced duration The length of time the migration user had a status of Synced.
Stalled duration The length of time the migration process was stalled for the user.
You also can use the remote Windows PowerShell in your Exchange Online Dedicated environment to display
migration user statistics using the Get-MigrationUser and Get-MigrationUserStatistics cmdlets. Within the
Exchange Online Dedicated environment, you must be a member of one of the role groups that provides access to
these cmdlets. To locate the role groups, search for the Get-MigrationUser and the Get-MigrationUserStatistics
cmdlets within the Self-Service Administration content held within the Exchange 2013 Platform Readiness area of the
Customer Extranet site for additional information.
Migration phases
To help you understand the migration status states described in the previous sections, it’s helpful to be familiar
with the phases of the migration process. The following table describes these phases and indicates whether the
phase is included in each type of migration.
Migration phase Hybrid Exchange migration
Initial synchronization – The migration
process migrates mailbox items to the newly
cloud-based mailboxes.
Yes
(includes calendar times and contacts)
Incremental synchronization - The migration
process synchronizes the on-premises mailbox
and the corresponding Exchange Online
mailbox every 24 hours.
Yes
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Migration Cmdlets Remote Windows PowerShell of Exchange Online Dedicated can be used to invoke cmdlets associated with migration
actions. The table below list all migration cmdlets available with Exchange Server 2013 and provides a description of
the subset of cmdlets available within Exchange Online Dedicated. The link provided for each applicable cmdlet points
to its full description within Microsoft TechNet.
Notes
1. To use the migration cmdlets, you need to be a member of specific administrative groups within your on-
premises Exchange organization and your Exchange Online Dedicated environment. See the above sections
Assign Permissions to Migrate Mailboxes to an On-premises Exchange Environment and Exchange Online
Dedicated Self-Service Migration Administrator account for additional information.
2. For the Set-MigrationBatch and New-MigrationBatch cmdlets, the StartAfter and CompleteAfter parameters
have been activated for Exchange Online Dedicated only. The parameter descriptions in the table below
supersede the descriptions shown in the TechNet article for each cmdlet.
Cmdlet Notes
Set-MigrationConfig This cmdlet is not exposed within Exchange Online Dedicated.
Get-MigrationUser
New-MigrationEndpoint
Get-MigrationStatistics
Get-MigrationEndpoint
Set-MigrationEndpoint
Get-MigrationUserStatistics
Set-MigrationBatch
The following exceptions apply to this cmdlet:
The StartAfter and CompleteAfter parameters have been activated for this
cmdlet only within Exchange Online Dedicated – see parameter
descriptions and usage examples below.1
Within the Detailed Description section, only Remote Move is applicable
for Exchange Online Dedicated.
Remove-MigrationEndpoint
Remove-MigrationUser
Complete-MigrationBatch
Export-MigrationReport
Remove-MigrationBatch
Test-
MigrationServerAvailability
Start-MigrationBatch
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Cmdlet Notes
Stop-MigrationBatch
Get-MigrationBatch
New-MigrationBatch
The following exceptions apply to this cmdlet:
The StartAfter and CompleteAfter parameters have been activated for
this cmdlet only within Exchange Online Dedicated – see parameter
descriptions and usage examples below.1
Within the Examples section, only example #3 (on-boarding remote
move migration) and example #4 (off-boarding remote move
migration) apply to Exchange Online Dedicated.
Within the Detailed Description section, only the Onboarding
remote move migration and Offboarding remote move
migration descriptions apply to Exchange Online Dedicated.
Get-MoveRequest
New-MoveRequest This cmdlet is not exposed within Exchange Online Dedicated.
Remove-MoveRequest This cmdlet is not exposed within Exchange Online Dedicated.
Resume-MoveRequest
Suspend-MoveRequest
Set-MoveRequest
Get-MoveRequestStatistics
1 Full descriptions of the StartAfter and CompleteAfter parameters and an example of their usage are the
following:
StartAfter Optional System.DateTime The StartAfter switch specifies whether to start the
mailbox move request at a future date and time. If
you use this switch, the request status is Queued
before the start date and time but will not reach the
status of InProgress until after the date and time
specified (see DateTime syntax in Example section).
You cannot set a date greater than 30 days into the
future.
CompleteAfter Optional System.DateTime The CompleteAfter switch specifies whether to
complete the database synchronization request at a
later date and time. If you use this switch, the
request status is Suspended and the request will not
reach the status of InProgress or Completed until
after the date and time specified (see DateTime
syntax in Example section). You cannot set a date
greater than 120 days into the future.
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This example schedules the move of a mailbox to a remote database to start 5 days from the current date and
sets the completion date for database synchronization to take effect 8 days from the current date.
[ As an alternative to using the Get-Date cmdlet, an explicit DateTime pair can be specified in
en-US format (e.g., 12/15/2013 or December 15, 2013 as the date and 7:30:00 PM (12 hour) or
19:30:00 (24 hour) as the time format) or UTC format (20131215193000.000000-480). ]
$Credentials = Get-Credential
$MigrationEndpointOnPrem = New-MigrationEndpoint -ExchangeRemoteMove -Name OnpremEndpoint
-Autodiscover -EmailAddress [email protected] -Credentials $Credentials
$OnboardingBatch = New-MigrationBatch -Name RemoteOnBoarding1 -SourceEndpoint
$MigrationEndpointOnprem.Identity -TargetDeliveryDomain cloud.contoso.com -CSVData
([System.IO.File]::ReadAllBytes("C:\Users\Administrator\Desktop\RemoteOnBoarding1.csv")) –
StartAfter (Get-Date).AddDays(5) -CompleteAfter (Get-Date).AddDays(8)
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Appendix A – Factors that affect Exchange Online Dedicated
migration performance
There are several paths available to migrate data between an on-premises email organization and Exchange Online
Dedicated. The following are the characteristics of the migration performance facts and migration velocity best
practices provided:
Details about how to migrate data and performance issue troubleshooting steps are not addressed.
High level descriptions are provided of external and on-premises factors; additional detail is provided for
Microsoft products and services.
The basis of the descriptions assumes there are no functional issues, connectivity exists between the source and
destination environments, and it is possible to successfully complete a migration between the two
environments.
Overview of Exchange Online Dedicated email migration
Exchange Online Dedicated provides a remotely hosted messaging solution based on Microsoft Exchange Server
2013. A feature of Exchange Online is the capability to migrate email, calendar, and contact data from your existing
messaging environment.
Migration methods available with Exchange Online Dedicated
Migration
tool
Description Example
Native
Office 365
simple
Exchange
migration
A built-in migration tool that
supports remote move migrations.
Migrating mailboxes between on-premises and
Exchange Online Dedicated via an Exchange hybrid
server or migrating mailboxes between the multi-
tenant version of Exchange Online and Exchange
Online Dedicated.
Client
uploading
Data can be uploaded from
various email clients that are
compliant with Office 365. This
method is mostly used on a small
scale and performed by individual
end users.
The user uploads an Outlook personal data file
(PST) from the Outlook client.
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Summary of observed migration performance
The following table compares the performance observed by Microsoft for methods available to migrate mailboxes
and mailbox data to the multi-tenant version of Office 365. The values shown can be used to determine an
approximate throughput for an Exchange Online Dedicated migration. Migration performance is a function of
several factors as described in the Overview of Exchange Online email migration performance factors section
below.
Migration
tool
Migration
method
Office 365
user
throttling
Office 365
migration-service
throttling
Office 365
resource
health-based
throttling
Observed average
throughput per hour and
per client (if applicable)
Native
Office 365
Hybrid
migration
No Yes Yes 10-15 GB (per on-premises
Exchange 2010 CAS (MRS
Proxy) with 20 concurrent
moves) *
Client
uploading
Outlook Yes No Yes 0.5 GB
Overview of Exchange Online email migration performance factors
Data migration is a complicated process. A summary of potential impacts is described within this section.
* Observed single mailbox move throughput is in the 0.3–1.0 GB/hour range. More concurrent
mailbox migrations can be used to achieve higher data migration rates. For example, with 50
concurrent moves, the overall throughput will be in the 15–50 GB/hour range. Single mailbox
move throughput will slow down when the on-premises CAS (MRS Proxy) server is at hardware
capacity. Consider adding more servers to increase migration velocity
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Common migration performance factors
The following table provides a list of common factors that affect migration performance. More details are covered
in the sections on the individual migration methods.
Factor Description Example
Data source The device or service that hosts the
data to be migrated. Many
limitations might apply to the data
source because of hardware
specifications, end-user workload,
and back-end maintenance tasks.
Third party providers hosting
Exchange mailboxes may limit how
much data can be extracted during a
specific period of time.
Data type and density Because of the unique nature of a
customer’s business, the type and
mix of mail items within mailboxes
vary greatly.
One 4-GB mailbox with 400 items,
each with 10 megabytes (MB) of
attachments, will migrate faster than
one 4-GB mailbox with 100,000
smaller items.
Migration server Many migration solutions use a
"jump box" type of migration server
or workstation to complete the
migration.
Customers often use a low-
performance virtual machine to host
the migration server.
Migration engine The data migration engine that is
responsible for pulling data from the
source server converts data if
necessary, transmits the data over
the network, and injects the data into
the Exchange Online mailbox.
Microsoft Exchange Mailbox
Replication Service (MRS).
Network The end-to-end network
performance—from the data source
to Exchange Online client access
servers—affects migration
performance.
Firewall on customer egress point.
Office 365 service Office 365 has built-in support and
features to manage the migration
workload.
The user throttling policy limits the
maximum data transfer rate.
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Network performance factors
This section describes best practices for improving network performance during migration. The discussion is
general because the biggest impact on network performance during migration is related to third-party hardware
and network configuration.
Performance factor Description Best practices
Network capacity The amount of time it takes to
migrate mailboxes to Exchange
Online is determined by the available
and maximum capacity of your
network.
Identify your available network
capacity and determine the
maximum upload capacity.
Use tools to evaluate your actual
network capacity. Make sure you
test the end-to-end flow of data,
from your on-premises data
source to the Microsoft data
center gateway servers.
Identify other loads on your
network (for example, backup
utilities and scheduled
maintenance) that can affect your
network capacity.
Network stability If the network is unstable, data
transfer takes longer because of
error correction. Depending on the
migration type, error correction can
significantly affect migration
performance.
Network hardware and driver
issues often cause network
stability problems. Work with
your hardware vendors to
understand your network devices
and apply the vendor’s latest
recommended drivers and
software updates.
Network delays Possible sources of network delays
that impact migration performance
include the following:
Configuration of network firewall
equipment
Use of the Internet (if required
for your migration)
Mailboxes being migrated from
several geographically dispersed
datacenters
Performance of your ISP (if
Exchange mailboxes are being
hosted by a third party)
Evaluate network delays to all
potential Microsoft data centers
to help ensure that the result is
consistent (this also helps ensure
a consistent experience for end
users). Work with your ISP to
address Internet-related issues.
Add IP addresses for Microsoft
datacenter servers to your allow
list or bypass all migration-
related traffic from you network
firewall.
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Office 365 resource health-based throttling
Health-based resource throttling is the last gatekeeper to ensure Office 365 service health and availability is
maintained. All migration methods are subject to the governance of availability throttling. Office 365 service
throttling does not affect Office 365 migrations as much as the other types of throttling described in the previous
sections.
Resource health-based throttling is the least aggressive throttling method and occurs only when there is a service
availability issue that affects end users and critical service operations. For example, if a service incident occurs during
a hybrid migration and the service degrades to the point where end-user performance is degraded, the hybrid
migration will be queued until performance has recovered and the service returns to a level below the throttling
threshold. The following is an example from an Exchange migration statistics report that shows an entry caused
when the service-throttling threshold is exceeded:
1/25/2012 12:56:01 AM [BL2PRD0410CA012] Copy progress: 723/1456 messages, 225.8 MB (236,732,045
bytes)/416.5 MB (436,712,733 bytes).
1/25/2012 12:57:53 AM [BL2PRD0410CA012] Move for mailbox '/o=ExchangeLabs/ou=Exchange Administrative
Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=xxxxxxxxxxxxxxxxxxxxxxxxxxxxx' is stalled because
DataMoveReplicationConstraint is not satisfied for the database 'NAMPRD04DG031-db081' (agent
MailboxDatabaseReplication). Failure Reason: Database edbf0766-1f2a-4552-9115-bb3a53a8380b doesn’t
satisfy constraint SecondDatacenter. There are no available healthy database copies. Will wait until
1/25/2012 1:27:53 AM.
1/25/2012 12:58:24 AM [BL2PRD0410CA012] Request is no longer stalled and will continue.
Native Office 365 hybrid migration
Native Office 365 hybrid migration supports migrations between on-premises Exchange 2003, Exchange 2007,
Exchange 2010, and Exchange 2013 servers and Exchange Online Dedicated. Hybrid migration is the fastest
migration method to migrate mailbox data to Office 365.
Migration performance factors and best practices
The table below provides a list of factors that apply to native Office 365 hybrid migration scenarios.
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Factor 1: Data source (Exchange Server)
Checklist Description Best practices
System performance Data extraction is an intensive task.
The source system must have
sufficient resources, such as CPU
time and memory, to provide better
migration performance. At the time
of migration, the source system is
usually close to full capacity to serve
regular end-user workload—
additional migration workload
sometimes even brings down end
users' access because of a lack of
system resources.
Monitor system performance
during a pilot migration test. If
the system is busy, we
recommend avoiding an
aggressive migration schedule
for the specific system because
of potential migration slowness
and service availability issues. If
possible, enhance the source
system performance by adding
hardware resources and reducing
the load on the system by
moving tasks and users to other
servers that aren’t involved in the
migration. For more information,
see Exchange 2007: Monitoring
Mailbox Servers and
Understanding Exchange
Performance.
When migrating from an on-
premises Exchange organization
where there are multiple mailbox
servers and multiple databases,
we recommend that you create a
migration user list that is evenly
distributed across multiple
mailbox servers and databases.
Based on individual server
performance, the list can be
further fine-tuned to maximize
throughput. For example, if
server A has 50 percent more
resource availability than server
B, it’s reasonable to have 50
percent more users from server A
in the same migration batch.
Similar practices can be applied
to other source systems.
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Checklist Description Best practices
Perform migrations when servers
have maximum resource
availability, such as after hours or
on weekends and holidays.
Back-end tasks Other back-end tasks that are
running during migration time.
Because it’s a best practice to
perform migration after business
hours, it’s common that migrations
conflict with other maintenance
tasks running on your on-premises
servers, such as data backup.
Review other system tasks that
might be running during
migration. We recommend that
you perform data migration
when no other resource-
intensive tasks are running.
Note: For customers using on-
premises Microsoft Exchange, the
common back-end tasks are backup
solutions and Exchange store
maintenance.
Factor 2: Migration server
Native Office 365 hybrid migration is a cloud-initiated pull/push data migration and an Exchange 2010
coexistence server acts as the migration server. If a low-scale virtual machine is used as the coexistence server,
the result will be poor migration performance.
Best practice
In addition to applying best practices previously described in the Data Source Server section, consider the
following to improve migration performance:
Use powerful server-class physical machines instead of virtual machines for the Exchange 2010 or Exchange
2013 coexistence servers. An example is the following:
o CPU: Intel® Xeon® CPU E5520 @ 2.27 GHz 2.26 GHz (two processors)
o Memory: 24 GB
o Disks: Eight at 146 GB per disk. RAID 5 configuration = 960 GB total raw space
Use multiple coexistence servers that are behind your on-premises network load balancer.
Configure MRS Proxy with a concurrency of 100.
Note
Disk performance is more important than available space for migration performance.
Factor 3: Migration engine
Native Office 365 hybrid migration uses native Office 365 tools that are subject to Office 365 resource health-
based throttling.
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Exchange 2003 vs. Exchange 2007 SP2 and Exchange 2010
There is a key difference for the end-user experience when the migration is from Exchange 2003. Unlike
Exchange 2007 SP2 and Exchange 2010, Exchange 2003 end users cannot access their mailboxes when their data
is being migrated; therefore, Exchange 2003 customers are usually more concerned about when to schedule
migrations and the time required to migrate – especially when migration performance is low because of large
mailbox sizes or a slow network. Exchange 2003 migration is also very sensitive to interruptions. If a service
incident occurs during the migration of an Exchange 2003 mailbox, the restart of intermediate servers involved
in the migration may be required. Migrations involving Exchange 2007 SP2 and Exchange 2010 tend to be more
resilient when service interruptions occur.
Best practice
Some customers choose to do two-hop migrations for large and sensitive Exchange 2003 mailboxes:
First hop Migrate mailboxes from Exchange 2003 to an Exchange 2010 server which is usually the
hybrid coexistence server. The first hop is an offline move, but it’s usually a very fast migration over a
local network.
Second hop Migrate mailboxes from Exchange 2010 to Office 365.
The second hop is an online move which provides a better user experience and fault tolerance. This two-
hop approach requires an Exchange 2010 license for the temporary on-premises Exchange 2010 user
mailbox.
Mailbox Replication Service Proxy (MRS Proxy)
MRS Proxy is the on-premises migration feature that works with the Mailbox Replication Service running within
Office 365 Dedicated. For more information, see Understanding Move Requests.
Best practice
The maximum number of MRS Proxy connections for the on-premises Exchange 2010 SP2 can be configured
using the following remote Windows PowerShell command:
Set-WebServicesVirtualDirectory -Identity "EWS (Default Web Site)" -MRSMaxConnections <number
between 0 and unlimited; default is 100>
Note
For most customer migrations, it’s unnecessary to change the default MRSMaxConnections value. If you
need to protect the source server from being overwhelmed by the migration load, customers can reduce
the number of connections. This setting is per MRS Proxy server. If you have two MRS Proxy servers, each
set to 10 connections, you will get 20 (2 x 10) total MRS Proxy connections. For more information about
configuring the MRS Proxy service in your on-premises Exchange 2010 organization, see Start the MRS
Proxy Service on a Remote Client Access Server.
Factor 4: Network
Network utilization at the time of the migration is a factor that dictates actual migration performance. Testing
network performance for hybrid migrations can be done by performing multiple test mailbox migrations.
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Factor 5: Office 365 service processes
Office 365 resource health-based throttling can affect the performance of migrations. The throttling impact is
based upon the priority of the migration type being executed as described in the following:
Onboarding move requests New customer migrations are considered onboarding move requests. These
requests have regular priority.
Data center internal move requests These are mailbox move requests initiated by data center operation
teams. These requests have a lower priority because the end-user experience isn’t affected if there’s a delay
in the move request.
When viewing migration status, the following provides an indication of migration processing performance
within Office 365:
Queued move requests This status specifies that the move has been queued and is waiting to be picked
up by the Microsoft Exchange Mailbox Replication service. For Exchange 2003 move requests, users can still
access their mailboxes at this stage.
Two factors influence which request will be picked up by Mailbox Replication service:
Priority Queued move requests with a higher priority are picked up before lower-priority move
requests. This helps ensure that customer-migration move requests always get processed before
data center internal move requests.
Position in the queue If move requests have the same priority, the earlier the request gets into
the queue, the earlier it will be picked up by the Mailbox Replication service. Since you may have
other self-service administrators performing mailbox migrations at the same time, it is normal for
new move requests to remain in the queue before they are processed.
Often, the time that mailbox requests wait in the queue before being processed isn’t considered during
migration planning. This results in customers not being allocated enough time to complete all planned
migrations.
In-progress move requests This status specifies that the move is still in progress. If this is an online
mailbox move, the user will still be able to access the mailbox. For offline mailbox moves, the user's mailbox
will be unavailable.
After the mailbox move request has a status of In Progress, the priority no longer matters and a new move
request won’t be processed until an existing In Progress move request is completed even if the new move
request has a higher priority.
For general information about getting status information for move requests, see View Move Request Properties.
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Best practices
Planning
As previously mentioned, because Exchange 2003 users lose access during a hybrid migration, Exchange
2003 customers are usually more concerned about when to schedule migrations and how long they will take.
When planning how many mailboxes to migrate during a specific time period, calculate the amount of time
the move request waits in the queue by using the following formula:
(total number of mailboxes to migrate) = ((total time) – (average queue time)) * (migration throughput)
In the above, migration throughput equals the total number of mailboxes that can be migrated per hour.
For example, assume you have a six-hour window to migrate mailboxes. If the average queue time is one
hour and you have a migration throughput of 100 mailboxes per hour, you can migrate 500 mailboxes in the
six-hour time frame: 500 = (6 – 1) * 100. Start the migration sooner than initially planned to mitigate time in
the queue. When mailboxes are queued, Exchange 2003 users can still access their mailboxes.
Determine queue time
The queue time is always changing because Microsoft does not manage migration scheduling. To determine
the potential queue time, you can try to schedule a test move several hours before the actual migration
starts. Then, based on the observed amount of time the request is in the queue, you can better estimate
when to start the migration and how many mailboxes can be moved in a specific period of time.
For example, if a test migration was completed four hours before the start of a planned migration and the
queue time was observed to be about one hour, then you should consider starting the migration one hour
earlier than originally planned to ensure there is enough time to complete all migrations.
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Appendix B – Using a CSV File for Mailbox Migration In addition to using the mailbox selection function of the EAC to prepare and execute a batch migration, you can use a
CSV file to migrate a large number of user mailboxes. You can specify a CSV file to create a migration batch to on-
board or off-board users when you use the Exchange Admin Center (EAC) or the New-MigrationBatch cmdlet in
remote Windows PowerShell. Multiple migration batches can be prepared for the remote move migration process.
Notes
1. When using the EAC selection function or a CSV file, the maximum number of mailboxes per migration
batch is 2000.
2. Both on-boarding and off-boarding remote move migrations are initiated from your Exchange Online
organization.
3. If the off-boarding source or on-boarding target is the multi-tenant version of Exchange Online, the EAC
migration tool must be launched from within the multi-tenant environment and the required Target
Endpoint must be indicated.
Supported attributes for CSV files for bulk moves or migrations
The first row (header row) of a CSV file used for migrating users contains the names of the attributes specified on
the rows that follow. Each attribute name is separated by a comma. Each row under the header row represents an
individual user and the information required for the migration of the user’s mailbox. The attributes in each individual
user row must be in the same order as the attribute names in the header row. Each attribute value is separated by a
comma. If the attribute value for a particular record is null, do not type anything for that attribute; however, make
sure that you include the comma to separate the null value from the next attribute.
Attribute values in the CSV file override the value of the corresponding parameter used when creating a migration
batch using the EAC or the remote Windows PowerShell. For more information and examples, see the section
Attribute values in the CSV file override the values for the migration batch below.
Tip:
You can use any text editor to create the CSV file. Using an application like Microsoft Excel will make it
easier to import data and configure and organize the CSV file. Be sure to save CSV files as a .csv or .txt file.
The following sections describe the supported attributes for the header row of a CSV file for each migration type.
Each section includes a table that lists each supported attribute, whether it’s required, an example of a value to use
for the attribute, and a description.
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Note
In the following sections, source environment denotes the current location of a user mailbox or a database.
Target environment denotes the location that the mailbox will be migrated to or the database that the
mailbox will be moved to.
On-boarding remote move migrations in a hybrid deployment
As described above in Mailbox Migration to/from Exchange Online Dedicated, you can move mailboxes from an
on-premises Exchange organization to Exchange Online Dedicated via a hybrid deployment. When on-boarding
mailboxes, the migration batch is created and executed from within the Exchange Online organization. The
following table describes the supported attributes for a CSV file for on-boarding remote move migrations.
Attribute Required or
optional
Accepted values Description
EmailAddress Required SMTP address
for the user
Specifies the email address for the mail-
enabled user in the Exchange Online
organization that corresponds to the on-
premises user mailbox that will be
migrated.
BadItemLimit1 Optional Unlimited or a
non-negative
integer from 0
(the default) to a
maximum value
of 2147483647
Specifies the number of bad items to
skip if the migration service encounters a
corrupted item in the mailbox. If you
include this attribute in the CSV file, it
will override the default value or the
value you specify if you include the
BadItemLimit parameter when creating
the migration batch using the EAC or
PowerShell.
Tip:
We recommend that you use the
default value of 0 and only
increase the bad item limit for a
particular user if the move or
migration for that user fails.
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Attribute Required or
optional
Accepted values Description
LargeItemLimit1 Optional Unlimited or a
non-negative
integer from 0
(the default) to a
maximum value.
Specifies the number of large items in
the user’s mailbox that will be skipped.
When the number of large items exceeds
this value, the migration for the mailbox
fails. The default value is 0, which means
that the migration fails if the mailbox
contains any large items. When on-
boarding mailboxes to Exchange Online,
items up to the maximum send/receive
message size for your environment are
migrated.
1The BadItemLimit and LargeItemLimit values can be set on a per user basis in the .csv file.
Off-boarding remote move migrations in a hybrid deployment
As described above in Mailbox Migration to/from Exchange Online Dedicated, you can move mailboxes from
Exchange Online Dedicated to an on-premises Exchange organization via a hybrid deployment. When off-boarding
mailboxes, a CSV file can be created for the migration batch. The following table describes the supported attributes
for a CSV file used for off-boarding migrations and for cross-forest enterprise remote moves.
Attribute Required
or optional
Accepted values Description
EmailAddress Required SMTP address
for the user
For cross-forest enterprise
moves, this specifies the
mailbox or mail-enabled
user in the source forest.
For off-boarding remote
move migrations, it specifies
the Exchange Online
mailbox.
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Attribute Required
or optional
Accepted values Description
TargetDatabase Required for off-
boarding remote
move migrations
that are initiated
from the source
forest.
Alternatively, this
attribute can be
specified when
creating the
migration batch
in the EAC or
using the Shell.
Database name Specifies the mailbox
database in the target forest
that the user’s primary
mailbox will be moved to.
You can specify a different
database in the different
rows of the CSV file, which
lets you move mailboxes in
the same migration batch to
different databases.
TargetArchiveDatabase Optional Database name This attribute is only
supported for off-boarding
remote move migrations.
Specifies the mailbox
database in the target forest
that the user’s archive
mailbox will be moved to.
You can specify a different
database in the different
rows of the CSV file which
will let you move archive
mailboxes in the same
migration batch to different
databases.
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Attribute Required
or optional
Accepted values Description
BadItemLimit Optional Unlimited or
a non-negative
integer from 0
(the default) to
a maximum
value of
2147483647
Specifies the number of bad
items to skip if the migration
service encounters a
corrupted item in the
mailbox. If you include this
attribute in the CSV file, it
will override the default
value or the value you
specify if you include the
BadItemLimit parameter
when creating the migration
batch using the EAC or the
Shell.
Tip:
We recommend that
you use the default
value of 0 and only
increase the bad item
limit for a particular
user if the move or
migration for that
user fails.
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Attribute Required
or optional
Accepted values Description
LargeItemLimit Optional Unlimited or
a non-negative
integer from 0
(the default) to
a maximum
value.
Specifies the number of
large items in the user’s
mailbox that will be skipped.
When the number of large
items exceeds this value, the
migration for the mailbox
fails. The default value is 0,
which means that the
migration fails if the mailbox
contains any large items.
When off-boarding
mailboxes to Exchange on-
premises, a large item is
defined by the transport
limits. To determine the
transport limit,, use remote
Windows PowerShell to
execute the following:
Get-TransportConfig |
Format-List
MaxReceiveSize
Attribute values in the CSV file override the values for the migration batch
Attribute values in the CSV file override the value of the corresponding parameter when that same parameter is
used when creating a migration batch with the EAC or the Shell. If you want the migration batch value to be
applied to a user, you would leave that cell blank in the CSV file. This lets you mix and match certain attribute
values for selected users in one migration batch. The example below shows how a batch can be created using a
CSV file for a cross-forest enterprise migration to move the primary and archive mailboxes of users to a target
forest:
New-MigrationBatch -Name CrossForestBatch1 -SourceEndpoint ForestEndpoint1 -TargetDeliveryDomain
forest2.contoso.com -TargetDatabases @(EXCH-MBX-02,EXCH-MBX-03) -TargetArchiveDatabases @(EXCH-MBX-
A02,EXCH-MBX-A03) -CSVData
([System.IO.File]::ReadAllBytes("C:\Users\Administrator\Desktop\CrossForestBatch1.csv")) -AutoStart
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Note
Because the default action is the move of the primary and archive mailboxes, you don’t have to explicitly
specify this action in the Shell command.
A portion of the CrossForestBatch1.csv file for this migration batch looks like the following:
Off-boarding Example CSV
EmailAddress,TargetDatabase,TargetArchiveDatabase
[email protected],EXCH-MBX-01,EXCH-MBX-A01
[email protected],EXCH-MBX-01,
...
Because the values in the CSV file override the values for the migration batch, the primary and archive mailboxes
for user1 are moved to EXCH-MBX-01 and EXCH-MBX-A01, respectively, in the target forest. The primary and
archive mailboxes for user2 are moved to either EXCH-MBX-02 or EXCH-MBX-03. The primary mailbox for user3
is moved to EXCH-MBX-01 and the archive mailbox is moved to either EXCH-MBX-A02 or EXCH-MBX-A03.
On-boarding Example CSV
New-MigrationBatch -Name RemoteOnboarding1 -SourceEndpoint ForestEndpoint1 -TargetDeliveryDomain
forest2.contoso.com -CSVData
([System.IO.File]::ReadAllBytes("C:\Users\Administrator\Desktop\CrossForestBatch1.csv")) -AutoStart
EmailAddress,BadItemLimit,LargeItemLimit
[email protected],200,200
...
Because the values in the CSV file override the values for the migration batch, the BadItemLimit and
LargeItemLimit for user 1 are different from other users and will not take the default values specified for the
batch defaults. For user2, we are accepting the default batch values for BadItemLimit and LargeItemLimit. For
User 3, we only need to override the BadItemLimit defaults for the batch.
The default value for BadItemLimit and LargeItemLimit is 0. For all migration scenarios, we recommend that you
accept the default value and only change the BadItemLimit parameter value if the move or migration fails for a
particular mailbox.
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Appendix C – Mailbox migration in a multi-region environment Within an Exchange Online Dedicated environment, a customer administrator is able to perform the self-service
migration of a valid mailbox type between Office 365 Dedicated datacenters located in other geographic regions.
Mailbox types that can be moved are standard user mailboxes as well as resource, shared, and inactive mailboxes.
Notes
1. An inactive mailbox must be temporarily assigned a user mailbox plan before it can be
migrated. Following the migration, the mailbox can be converted back to an inactive type.
See the MAILBOX PROVISIONING ATTRIBUTE section of the Office 365 Dedicated and
ITAR-support Plans Provisioning Tools Handbook for additional information regarding how
to set the characteristics of a mailbox.
2. A public folder mailbox must be migrated by Microsoft Online Services using the
Configuration Request process. Contact your Microsoft Service Delivery Manager for
assistance.
Preparation
Prior to invoking the mailbox migration, the RegionCode for the source mailbox must be set to the value that
represents the destination region. The value is set by executing the Set-Mailbox cmdlet using remote Windows
PowerShell as shown in the syntax example below.
Set-Mailbox –Identity <MailboxIdParameter> -MailboxProvisioningConstraint "{Region -eq '<RegionCode>'}"
Identity parameter specifies the mailbox using a format as described in the Set-Mailbox cmdlet description
(see Parameters section of description).
MailboxProvisioningConstraint parameter is available only within the Exchange Online Dedicated
(parameter is not shown within Microsoft TechNet description). Valid RegionCode values are the following:
O365D Datacenter Mailbox Provisioning Constraint
RegionCode Value
Asia-Pacific APC
Europe EUR
North America NAM
Important
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1. Within Exchange Online Dedicated, a mailbox is initially provisioned using the mailbox
provisioning attribute. The provisioning attribute is an Active Directory extension attribute (also
referred to as an Exchange CustomAttribute) associated with an AD user object. The provisioning
attribute contains a flag that sets the initial geographic region value (REG=<value>) for the mailbox.
The value options for REG= are not the same as the value options for the RegionCode used in the
MailboxProvisioningConstraint value.
2. When the Set-Mailbox cmdlet is used to set the region code for the mailbox, the
MailboxProvisioningConstraint value becomes the authoritative value within Exchange Online
Dedicated that identifies the regional location of the mailbox. Following the step to set the
MailboxProvisioningConstraint value, recommended is the removal of the REG= value in the
mailbox provisioning attribute.
For more information describing the use of the mailbox provisioning attribute, see the MAILBOX
PROVISIONING ATTRIBUTE section of the Office 365 Dedicated and ITAR-support Plans Provisioning Tools
Handbook.
Execution
In Exchange Online Dedicated, the load balancing service on every mailbox server manages the execution of the
migration. Within 24 hours of the MailboxProvisioningConstraint value being set, the move will be scheduled
by the service. The actual time required to complete the migration depends upon the mailbox type and size. Most
moves typically are completed by the migration service within 24 hours of being scheduled. The mailbox will be
moved onto a database that matches the MailboxProvisioningConstraint value.
Note
The execution of the migration will be blocked if a move request is pending for the mailbox.
Use the Remove-MoveRequest cmdlet to delete the move pending move request.
Verification
To validate the completion of the migration, the following can be executed using remote Windows PowerShell:
Get-Mailbox <Identity> |fl database,mailboxprovisioningconstraint
Identity parameter specifies the mailbox using a format as described in the Get-Mailbox cmdlet description
(see Parameters section of description).
An example of the data returned is the following:
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Database : NAMSR99DG001-db013
MailboxProvisioningConstraint : {Region -eq 'EUR'}
Example of how to audit mailboxes by region (example illustrates search for all mailboxes located in the European
region):
Get-Mailbox -ResultSize Unlimited | ? {$_.MailboxProvisioningConstraint -eq "Region -eq 'EUR'"}
Troubleshooting
The migration service will not complete the mailbox move if any of the following conditions exist:
Error Corrective Action
The legacy region code parsed from
the customAttribute
"<value_strings>" is invalid
Correct the REG value in the mailbox provisioning attribute for
the object to be one of the following:
REG=AP;
REG=EU;
REG=NA;
Incorrect
MailboxProvisioningConstraint
value set on the mailbox
Correct the MailboxProvisioningConstraint value to be one
of the following:
"{Region -eq 'APC'}"
"{Region -eq 'EUR'}"
"{Region -eq 'NAM'}"
There is no database with
MailboxProvisioningAttributes
satisfying the
MailboxProvisioningConstraintEntry:
'Region –eq 'value’ ‘
Migration service is unable to verify existence of a database in
the destination region; contact Microsoft Online Service Support
if the database should be available or adjust the Region value to
a valid regional database
Move request exists for the mailbox Use Remove-MoveRequest to delete the move pending move
request