Tutorial: Migration Manager at Scale¶

Status: Authored 2026-04-30 Audience: M365 administrators and migration leads managing large-scale SharePoint on-premises to SharePoint Online migrations using Migration Manager in the Microsoft 365 admin center. Scope: Agent installation, centralized scanning, bulk migration scheduling, monitoring dashboard, and at-scale operations.

Prerequisites¶

Before starting this tutorial, ensure:

• Microsoft 365 tenant with SharePoint Online provisioned
• Global Administrator or SharePoint Administrator role
• One or more Windows servers/workstations for Migration Manager agents
• Network connectivity from agent machines to source SharePoint farms and SPO
• Entra Connect configured and syncing users
• Agent machines: Windows Server 2016+ or Windows 10/11, 8 GB RAM, 50 GB free disk

Step 1: Access Migration Manager¶

1.1 Navigate to Migration Manager¶

1. Open the Microsoft 365 admin center: https://admin.microsoft.com
2. In the left navigation, expand Settings and click Migration
3. Or navigate directly to the SharePoint admin center > Migration
4. Select SharePoint Server as the migration source

1.2 Migration Manager vs SPMT¶

Step 2: Install Migration Manager agents¶

2.1 Download and install agents¶

1. In Migration Manager, click Set up agents
2. Click Download agent setup file to get the installer
3. Run the installer on each agent machine

# Download the agent installer
# The download link is provided in the Migration Manager UI

# Install silently (optional)
.\MigrationAgentSetup.exe /quiet /norestart

# The agent registers with your M365 tenant during installation
# You will be prompted to sign in with admin credentials

2.2 Agent placement strategy¶

2.3 Agent requirements per machine¶

• Windows Server 2016/2019/2022 or Windows 10/11
• 8 GB RAM minimum (16 GB recommended for heavy loads)
• 50 GB free disk space for temporary staging
• .NET Framework 4.6.2+
• Network: outbound HTTPS to _.sharepoint.com, _.microsoftonline.com, *.blob.core.windows.net
• Network: access to source SharePoint farm (HTTP/HTTPS)

2.4 Verify agent status¶

After installation, agents appear in the Migration Manager dashboard:

1. Navigate to Migration Manager > Agents
2. Verify each agent shows Available status
3. Check agent version is current
4. Monitor agent health (CPU, memory, network utilization)

# Check agent service status on the agent machine
Get-Service -Name "SharePoint Migration Agent" | Select-Object Status, StartType

Step 3: Scan source environment¶

3.1 Add source sites for scanning¶

1. In Migration Manager, click Add source
2. Enter the root URL of your SharePoint farm: https://sp2016.contoso.com
3. Provide credentials (farm administrator or site collection administrator)
4. Migration Manager discovers all site collections under the root

3.2 Bulk add sources via CSV¶

For large environments with multiple farms or web applications:

SourcePath,TargetPath,TargetList,TargetListRelativePath
https://sp2016.contoso.com/sites/finance,https://contoso.sharepoint.com/sites/finance,,
https://sp2016.contoso.com/sites/hr,https://contoso.sharepoint.com/sites/hr,,
https://sp2016.contoso.com/sites/legal,https://contoso.sharepoint.com/sites/legal,,
https://sp2016.contoso.com/sites/marketing,https://contoso.sharepoint.com/sites/marketing,,
https://sp2016.contoso.com/sites/engineering,https://contoso.sharepoint.com/sites/engineering,,
https://sp2013.contoso.com/sites/archive,https://contoso.sharepoint.com/sites/archive,,
https://sp2013.contoso.com/sites/projects,https://contoso.sharepoint.com/sites/projects,,

1. Click Bulk upload in Migration Manager
2. Upload the CSV file
3. Migration Manager validates each source/target pair
4. Invalid entries are flagged for correction

3.3 Run assessment scan¶

1. Select all source sites in the list
2. Click Scan to start assessment
3. Migration Manager agents scan each site and report:
   • Total size (with and without versions)
   • File count
   • List count
   • Blocked items (unsupported file types, path too long)
   • Warnings (checked-out files, InfoPath forms, workflows)

3.4 Review scan results¶

The scan dashboard shows:

Export scan results for detailed analysis:

1. Click Download report to get CSV export
2. Review blocked items and determine remediation plan
3. Sort by size to plan wave order

Step 4: Configure migration settings¶

4.1 Global settings¶

In Migration Manager, configure settings that apply to all migration tasks:

1. Navigate to Settings in Migration Manager
2. Configure:

4.2 Performance tuning¶

# Migration Manager automatically balances load across agents
# To optimize throughput:

# 1. Run migrations during off-hours to avoid SPO throttling
# 2. Deploy agents close to the source (same network segment)
# 3. Ensure sufficient bandwidth (100 Mbps+ per agent recommended)
# 4. Reduce version count if speed is critical
# 5. Exclude large media files that can be migrated separately

Step 5: Schedule and execute migration¶

5.1 Create migration batches¶

Group sites into migration batches based on:

• Wave 1: Pilot sites (3-5 small, low-risk sites)
• Wave 2: Standard team sites (simple content, no customizations)
• Wave 3: Sites with managed metadata and content types
• Wave 4: Publishing sites and intranet
• Wave 5: Complex sites (workflows, InfoPath, custom solutions)

5.2 Schedule migrations¶

1. Select sites for a batch in Migration Manager
2. Click Schedule migration
3. Choose start time (recommend off-hours: weeknights or weekends)
4. Set migration window (e.g., Friday 6 PM to Monday 6 AM)
5. Enable incremental migration for subsequent runs

5.3 Execute migration¶

1. Click Start migration for the selected batch
2. Migration Manager distributes tasks across available agents
3. Each agent processes assigned sites concurrently
4. Progress is updated in real-time on the dashboard

5.4 Monitor during migration¶

The Migration Manager dashboard provides real-time monitoring:

Step 6: Review results and remediate¶

6.1 Post-migration reports¶

After each batch completes:

1. Click View report for the completed batch
2. Review summary: items migrated, failed, skipped
3. Download detailed report CSV for analysis

6.2 Error triage¶

6.3 Incremental re-run¶

1. In Migration Manager, select the completed batch
2. Click "Run incremental migration"
3. Only changed and previously failed items are processed
4. Review updated results
5. Repeat until all items are migrated successfully

Step 7: At-scale operations¶

7.1 Managing 1,000+ sites¶

For enterprise-scale migrations with thousands of sites:

1. Automated source discovery:

   # Generate source list from on-premises farm
   Add-PSSnapin Microsoft.SharePoint.PowerShell
   
   Get-SPSite -Limit All | ForEach-Object {
       [PSCustomObject]@{
           SourcePath = $_.Url
           TargetPath = $_.Url -replace "https://sp2016.contoso.com",
                                        "https://contoso.sharepoint.com"
       }
   } | Export-Csv -Path "C:\Migration\bulk-sources.csv" -NoTypeInformation
   

2. Wave planning by size:

   # Sort sites into waves by size
   $sites = Import-Csv "C:\Migration\site-inventory.csv"
   
   $wave1 = $sites | Where-Object { [int]$_.StorageMB -lt 1024 }   # < 1 GB
   $wave2 = $sites | Where-Object { [int]$_.StorageMB -ge 1024 -and [int]$_.StorageMB -lt 10240 }  # 1-10 GB
   $wave3 = $sites | Where-Object { [int]$_.StorageMB -ge 10240 -and [int]$_.StorageMB -lt 102400 } # 10-100 GB
   $wave4 = $sites | Where-Object { [int]$_.StorageMB -ge 102400 } # > 100 GB
   
   Write-Host "Wave 1 (< 1 GB): $($wave1.Count) sites"
   Write-Host "Wave 2 (1-10 GB): $($wave2.Count) sites"
   Write-Host "Wave 3 (10-100 GB): $($wave3.Count) sites"
   Write-Host "Wave 4 (> 100 GB): $($wave4.Count) sites"
   

3. Parallel execution: Migration Manager automatically distributes work across agents. Add more agents to increase throughput.

7.2 Multi-farm migration¶

For organizations with multiple SharePoint farms (common in large enterprises and government):

1. Deploy agents near each farm's network segment
2. Add each farm as a separate source in Migration Manager
3. Create per-farm migration batches
4. Schedule to avoid cross-farm network contention

7.3 Monitoring dashboard best practices¶

• Check the dashboard every 2-4 hours during active migration
• Set up email alerts for failed tasks (configured in Migration Manager settings)
• Export daily reports for stakeholder communication
• Track cumulative progress against the migration plan

Step 8: Decommission agents¶

After migration is complete:

1. Verify all migration tasks show Completed status
2. Run a final incremental migration to capture any last changes
3. Validate content in SPO
4. Uninstall Migration Manager agents from agent machines:

# Uninstall agent
# Use Programs and Features or:
.\MigrationAgentSetup.exe /uninstall /quiet

1. Remove agent registrations from Migration Manager dashboard
2. Set source SharePoint sites to read-only
3. Document final migration metrics for the project record

Migration Manager limits and quotas¶

References¶

• Migration Manager documentation
• Migration Manager agent setup
• Migration Manager FAQ
• Migration Manager performance
• Bulk upload sources
• SharePoint Online throttling

Maintainers: csa-inabox core team Last updated: 2026-04-30