Prior to any migration taking place, a pre-migration planning stage is crucial to assess the content and structure of public folders, identifying any potential issues that could arise during migration. Areas to review include:
- Security of existing folders
- Sizing of existing folders, cleaning up or removing old data
- Archiving, retiring old public folders
- Cost, IT involvement and third-party licenses, if chosen
Additionally, it’s important to determine the required permissions and access rights for users to access public folders in Exchange Online, which may involve reconfiguring these settings before starting the migration process.
Once pre-migration planning has been completed, migration can start and, like any process, issues may arise – not only with Exchange 2010 itself but with any clients upgrading to Exchange Online as well.
Selecting Migration Tools
Selecting an effective migration tool for your enterprise is of utmost importance. Microsoft provides public folder migration scripts as a starting point; I've found them effective; however, for more complex moves utilizing third party tools like Bittitan or Skykick has proven more manageable. The utilization of third-party tools not only facilitates scheduling of migrations but also enables more efficient detection and resolution of migration errors. Moreover, the tools are fully compatible with the migration API, which considerably enhances the level of detail in the error logs, thereby significantly easing the troubleshooting process.
Deprecating Basic Authentication
Microsoft has recently deprecated basic authentication in Office 365 and Exchange Online, making the migration of legacy Public Folders challenging. Recently, in collaboration with Microsoft, we were able to get Microsoft to approve a policy exception allowing on-premises basic authentication access for moving folders.
If moving legacy Exchange 2010 to Exchange Online, Microsoft may not approve of a policy exception. You may have to work with either Microsoft to move your public folders to Exchange Online or with a third-party provider to bypass the Basic Authentication issues presented by Exchange 2010. This needs to be investigated and planned for before any migration can take place.
Large Public Folders Synchronization
Migrating large amounts of data to Exchange Online can put undue strain on your network bandwidth, leading to connectivity and bandwidth issues during migration. For optimal results, we advise performing migration during off-peak hours when network bandwidth availability is sufficient, scheduling migration jobs during off-peak hours when it will impact your users the least.
Synchronization of Large Public Folders and Related Metadata
Migrating large public folders may take significant time and can be particularly complex if they contain associated metadata like calendar appointments or tasks. To address this challenge, consider how you organize the migration during your pre-migration planning. Try incremental migration methods and breaking large folders down into smaller chunks. This will provide an easier migration experience.
Permissions and Access Control Management
As mentioned in pre-migration planning, simplifying permissions and access control management where possible will be helpful as migrating without causing disruption to users can be an intricate process if there are many users and groups requiring different levels of access. Therefore, it is vital to plan carefully to maintain all permissions during migration.
Resolution of Conflicts and Errors during Migration
While migrating data between folders, you may run into conflicts or errors that prevent successful migration of public folder data. Therefore, it’s crucial you closely monitor migration processes and output logs to address any conflicts or errors.
Migration Delta Synchronization
If you are not prepared to fully sunset Exchange 2010 after your migration is complete, be sure all the data remains synchronized between Exchange Online and any remaining Exchange 2010 servers. This may prove challenging if your folder structures contain complex folder structures with large volumes of information requiring updating.
Whether using Microsoft’s solution with PowerShell or a third-party application, each can be used to keep a delta synchronization in place. A delta synch only adds in new data to the migration since the first migration – and is much less stressful than doing a full migration.