While you can run save-while-active operations any time, save-while-active operations will affect the performance of other applications you are running. Therefore you should run save-while active operations during times of low server activity. A few interactive jobs or batch jobs that are primarily read-only, are examples of activities that allow better server performance during the save-while-active operation.
In general, the server performs checkpoint processing faster for a small number of larger objects than for a large number of smaller objects.
You should not use the save-while-active function when the server is very busy or when there is very little disk storage available. Before you save large amounts of data (such as all user libraries), you should initially use the save-while-active function on a limited amount of data. Using the save-while-active feature on a limited amount of data will help you determine its impact on your server's performance and storage.