Out-of-memory errors can occur when the JVM does not have an adequate amount of native memory space.
Confirm that enough native memory is available to the Java™ Virtual Machine (JVM). Enough memory includes memory for the maximum heap size and additional memory required by the JVM, such as the Just-In-Time compiler, and other native code. To be safe, set the amount of native memory allocated for the JVM process to no more than 60% of the per process memory limit as dictated by the operating system and application server.
The required amount of additional memory required by the JVM process varies for each environment. However, 25 percent of the maximum heap size is a reasonable guideline. For example, if the maximum heap size is set to 1 GB, give the native memory for the JVM process to at least 1.25 GB.
By applying these rules, an example of a JVM running on 32- bit Windows with 2 GB of memory available to any single process might use the following minimum and maximum settings: