title: What does Java start the heap at if I do not specify a -Xms?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/4667483/how-is-the-default-java-heap-size-determined">How is the default java heap size determined?</a>  </p>
  </blockquote>
  
  
  
  <p>Im curious what happens if I do not specify a <code>-Xms</code> for initial JVM heap size with Java?</p>
  
  <p>Currently I have <code>-Xms256m and -Xmx512m</code> but this gives me an error on my server :</p>
  
  <pre><code>Failed to create JVM, return code is:-1
  </code></pre>
  
  <p>I believe the JVM is having trouble getting 256MB of contiguous memory with a 256m starting point.  Prior to today we only had a <code>-Xmx256m</code> setting but had some processes that were running out of memory.  </p>
  
  <p>Can the JVM function if I remove the <code>-Xms</code> setting and just leave the <code>-Xmx512m</code>'?  What does the heap start with?  </p>
  
  <p><strong>How does it acquire contiguous memory if no starting heap is declared?</strong></p>