What are the key steps to follow when migrating a large on-premises file share to SharePoint Online while minimizing disruption to end users?

Migrating a large on-premises file share to SharePoint Online with minimal disruption requires careful planning and execution. First, perform a thorough assessment of the existing file share. Analyze the file structure, size, permissions, and usage patterns. Identify any obsolete or redundant files that can be excluded from the migration. Plan the SharePoint Online site structure. Determine how the on-premises file shares will be mapped to SharePoint sites, document libraries, and folders. Consider using hub sites to provide a centralized navigation and search experience. Clean up and prepare the data. Remove unnecessary files, correct any inconsistencies, and ensure that file names are compatible with SharePoint Online's naming conventions. Address any permission issues and map on-premises user and group permissions to SharePoint Online permissions. Choose a migration tool. Use the SharePoint Migration Tool, a third-party migration tool, or PowerShell scripting to transfer the files to SharePoint Online. Consider a phased migration approach. Migrate data in smaller batches to minimize the impact on end users. Start with less critical data or pilot groups. Implement a delta migration strategy. After the initial migration, perform incremental migrations to capture any changes made to the files during the migration process. Communicate with end users. Provide clear communication about the migration schedule, any expected downtime, and how to access the files in SharePoint Online. Provide training and support to help users adapt to the new environment. Once the migration is complete, verify the data integrity. Ensure that all files have been migrated successfully and that permissions are correctly configured. Update any links or shortcuts that point to the old file share location. Finally, decommission the on-premises file share. Once you have verified that everything is working correctly in SharePoint Online, decommission the on-premises file share to avoid confusion and ensure that users are accessing the correct files.