The Configure Logs window allows you to determine the number of SQL Server Logs retained by SQL Server. You can access this window by clicking Configure on the Logs tab.
Check the Unlimited check box to retain all Event Logs or enter the number to keep only a number of the most current logs. SQL Diagnostic Manager deletes older logs.
The number indicated on the Configure Server Logs window changes the number of SQL Server Logs stored by SQL Server, but not the number of SQL Server Agent logs stored.