User Profile Synchronization service re-provision

Question

User profile synchronization service stuck on status 'starting' in our SharePoint 2013 farm. It causes many issues. One of those issues are: Secondary domain users are not getting workflow generated emails We tried to sync the service by running stsadm -o sync but it didn't work. Now, we want to re-provision the User Profile Synchronization service. If we do that, what are the challenges we might face? Will there be any complex issues? Need expert's opinions.

Answer 1

If you do not have customization on user profile sync, re-provision is no harm. What UPS do is simply copying the user data from AD to SharePoint's user profile database. As you can see, rebuild the database and re-copying again is no harm.

Answer 2

In my opinion, there is no negative impact on the SharePoint farm.

And you could use below PowerShell to stop User Profile Synchronization service then restart it.

$Service = Get-SPServiceInstance | where {$_.TypeName -eq "User Profile Synchronization Service"}  
$Service.Unprovision()