Java heap start (-Xms) in practice

The discussion on start (-Xms) and maximum (-Xmx) heap memory in Java is and old one. The consensus among admins is that both settings are best set to equal values in order to prevent internal Java reorganizations when heap changes are required. Before you follow this advice, you best understand that the starting heap is not fully claimed at the OS level and also that some garbage collection runs may not be triggered at all in your application.