Thomas.Poett@TEAMS (MVP Teams and Cross-Tenant M&A/D Migration Expert Lead)

  Example of our user data migration approach: Important is the completion of your data pre-load for OneDrive and Exchange. Remember, that the pre-load should include as much data as possible. Syncing on the cut-over day data > 10 GB or more than 500 files in OneDrive, might end up with an INCOMPLETE set of data in the target. Therefore, you should urge using the OneDrive Cross-tenant OneDrive Migration tool from Microsoft. The user will than see data being migrated (missing data) upon he starts working in the target environment. This will not be happening with the cross-tenant migration tool. The switch to the target tenant will take approx. 15min. Migration of Teams personal Chat messages, we mostly limit to 15 days. The performance is acceptable migrating approx. 400 – 800 users/day. Note: You should have special procedures in place for legal-hold users, white glove and user object facing issues. Prepare source and target tenant and ensure the readiness for Microsoft...

  Personal Data migration OneDrive In the previous chapters, it is stated: Teams make use of several M365 service. Especially for the personal side of Teams, Exchange and OneDrive are heavily involved. Towards Teams migration, it is required, that ALL data is present in the target environment for Exchange Calendar and OneDrive (shared files). Data Pre-Load Data pre-load is much slow than you expected. This is the most important lesson learned. While Exchange is faster than OneDrive, be aware of the time required for the data copying process. Another important statement is: none of the existing solutions are SYNC solutions, data is only copied. Therefore, a co-existence and working parallel in both, source and target tenant can lead to data inconsistence. If data is changed in the target environment and in source, any delta sync will overwrite the target data, if source has a new change date. Same, if the target data is newer, changed source data will not be copied. ...