AX 2012 to D365 F&O Data base upgrade best practices / things to look at.

Database upgrade in lift and shift upgrades runs with SQL replication process. Steps for this process are very well documented here - https://docs.microsoft.com/en-us/dynamics365/fin-ops-core/dev-itpro/migration-upgrade/data-upgrade-self-service

Ax 2012 Data upgrade in self-service enviornment tech talk can be found here (https://community.dynamics.com/365/dynamics-365-fasttrack/b/techtalks/posts/techtalk-ax2012-data-upgrade-in-self-service-environment-july-16-2021)

 Below you can find some learning from my experience on using AX 2012 database upgrade toolkit and overall data upgrade process.

1. Old backpac process is no longer supported. Only way to upgrade data is using AX 2012 Database Upgrade Toolkit which uses SQL replication process.
2. Make sure to check version of the SQL server for Ax 2012. SQL server 2008 and older are not supported by AX 2012 Database Upgrade Toolkit for snapshot replication process.
3. If SQL version is 2008 or older recommend customer to upgrade to their production SQL to SQL 2012 are higher at the beginning of the project.
4. Make sure to have your tier 2 environments deployed with blank DB. If you deploy it with Contoso data, target clean up DB step takes time.
5. When replication shows “No replicated transactions available” your replication snapshot is done, and you don’t have to wait for any other processes to execute.

1. If you see above message make sure console shows replication snapshot completed for both publications.
2. Remove function WHSinventreseveuniondelta – this function is not supported by tool kit.
3. Disable all triggers on Self-service environments before step 10 otherwise upgrade fails. Once upgrade is complete enable all triggers.
4. Having data in DAT company causes step 10 to fail, so make sure not to have any data in DAT company. For example, a single record in Document Type table causing upgrade to fail.
5. Executing cleanup routines on the source DB is required step and should be done with proper planning before iteration first of database upgrade starts.

Improving replication snapshot performance.

Visit following doc article to check how you can improve replication performance on the  distributor server.

 https://docs.microsoft.com/en-us/sql/relational-databases/replication/administration/enhance-general-replication-performance?view=sql-server-ver16

That’s all for now. Feel free to ask any questions you might have on the upgrade process in the comments section.