Installation of Lync server 2013 database update failed with error "Set owner failed for Database 'rtcxds'."
Command used to update the Lync database "Install-CsDatabase -ConfiguredDatabases -SqlServerFqdn FEBE.FQDN -Verbose "
Looking more closer to the error message and the log file it created, Its clear that while updating the database its complaining that "The login 'sa' does not exist on this server". As i imagined SQL is been hardened after we implemented Lync initially. We started looking at the SQL server for SA user and came to know this user is been renamed to some other name and disabled as per the internal hardening guidelines.
Rename the SA account back to SA
Additional Notes :
We renamed the SA account back to SA but kept it disabled as it was disabled by our SQL team. Looks like Lync database update process do check for SA account is presented in the server and if its not presented, it will fail.