Now a part 2 of this is available you can read here https://synkventures.com/2019/06/09/impact-of-active-directory-migration-or-domain-change-on-sharepoint-domain-migrate-sharepoint-servers-part-2/
There can be situations when your organizations decides to change name due to mergers, acquisitions or splits. In this case quite often users are migrated from one active directory to other. This will definetely have impact on SharePoint users, servers and configurations.
Generally active directory migrations are done in two steps
- Migrate users and computers
- Migrate servers and service accounts
This post will cover the first point, second one will be covered in second post.
Generally when users are migrated in active directory you would expect that Microsoft products will be handled automatically but strangely that is not the case with SharePoint due to the reason User Profile service works in SharePoint. Reason is that User Profile Service does not work with Secuirty Identifier (SID history).
Before you migrate the users another thing which needs to be taken care is that all the Web Applications needs to allow new domain to do that please refer to below TechNet article
When users are migrated in Active Directory, SharePoint has provided a command to migrate the users in SharePoint as well.
To migrate user in the whole farm use below command
$farm = Get-SPFarm
$farm.MigrateUserAccount( $_.oldlogin, $_.newlogin, $false )
Note that old login and login should be read like below