ODM Slow migration Possible factors (4377694)

What are the possible factors for slow Migration progress?

Time-Consuming Factors to Consider in Migration

ALL ODM Migration module

• Microsoft Bandwidth/Throttling and API Call Limits
  Microsoft’s API throttling limits the number of requests processed simultaneously, which can slow down migrations. Additionally, Graph API has request quotas, and exceeding these limits can lead to temporary blocks, causing delays.

Email (EWS)

• Microsoft EWS Throttling
  Exchange Web Services (EWS) has built-in throttling policies to manage resource usage. These limits restrict the number of concurrent connections, message transfers, and API requests, which can delay mail migration. Tenant Admin should be able to "Request an upgraded Office 365 throttling policy from Microsoft to achieve the best migration throughput and performance" from This KB  for both source and target.

Onedrive/Sharepoint/Teams/Group (Graph API)

• Number of Items on the Sharepoint Sites
  A site containing millions of small files will require significant time for the API to batch and process the items.
• Size of Each Object
  Large files are migrated in chunks, and the size of the files impacts how many API calls are required for complete migration. This is especially relevant for files nearing SharePoint's size limits.
• The Complexity of the SharePoint Structure
  Sites with deeply nested folders or a complex hierarchy will take longer due to the need to traverse and replicate the structure.
• Complexity of the SharePoint Permissions
  Sites with custom or non-inherited permissions require additional processing to maintain security settings during migration, increasing migration time.
• Versioning of Files and Documents
  Files with multiple versions demand additional API calls to transfer and maintain all historical data.
• Post-migration Validation
  The time taken to verify migrated content for accuracy, integrity, and permissions alignment can also contribute to the overall duration.
  

   

Teams (Graph API)

• Numbers of Channel of the Teams
  If a Team contains multiple channels, the migration process will take longer as each channel requires separate API calls for data retrieval, processing, and migration. The complexity increases further if channels have extensive content, custom tabs, or associated files.

** Always refer to best practice documents that are available on our official web here. Document name "On Demand Migration Strategy and Best Practices for Migrating Active Directory, Mail, OneDrive, SharePoint Online, and Teams Content (version x.x)"