The JAVADUMP is a text file that you can read without any tool. It contains three major distinct sections: Runtime environment Current thread details, operating environment, application environment, loaded libraries, exception information, and system properties Thread dumps Full thread dump Monitor information Monitor pool info, monitor pool dump, JVM system monitor dump, thread IDs, Java object monitor dump JAVADUMP detail analysis is described in "Dump analysis and tools" on page 193. HEAPDUMP is an IBM JVM-specific mechanism that generates a dump of all the live objects that are on the Java heap; that is, those that are being used by the running Java application. From IBM SDK for z/OS Java 2 Technology Edition, V1.4 SR2, this dump is stored in a file using phd format. You can use various tools to analyze the dump file to address a problem such as memory leak. A HEAPDUMP can be generated from a running JVM in the following ways: Explicit generation of a HEAPDUMP