Welcome to the part2 of the Migrate Active Directory 2008 R2 to Active Directory 2012 blog series. In this post, i will run some prerequisites and validation tests before proceeding with the migration. Tests are primordial because if the state of your current active directory is not good, migration may fail and you can encounter many errors and unexpected behavior during or after the migration.
In addition, you should review the following link, and see if your current environment is ready for migration aka upgrade
Before continuing : Connect to all your domain controllers, and clear the following event logs: System, DFS Replication, Directory services, DNS. Wait for more than 60 minutes before proceeding with this guide. Check your event logs and look for any AD related errors or warnings.
Important: Every step should be run on each domain controller. Logon to to the domain controller with a user member of the domain admins security group. From an elevated command prompt, run the following commands:
- ‘Dcdiag.exe /v’ or ‘Dcdiag.exe /v /f:Dcdiag.txt’ if you want that the command output be redirected to text file. take your time to focus on the results and try to investigate any error or problem before continuing.
- ‘Repadmin /showreps’ This command will output you the replication status between the domain controllers. Verify that all the status are Successful
- ‘Repadmin /replsum‘ This command let you see the replication stats and let you know if there’s any error.
Now, we have checked our current Active Directory platform and we are now ready for migration. Yesss!!
NB: The commands written before are not all the commands for diagnosing ADDS, there’s many other commands and tools