title: 'Could not reserve enough space for object heap' when running java -version
body: <p>I know this is a common question/problem. I'm wondering where to get started with it. </p>
  
  <p>Running java on windows server 2008, we have 65GB memory, and it shows 25GB free. (Currently a couple of guys are running processes). </p>
  
  <p><code>systeminfo | grep -i memory</code></p>
  
  <p>shows:</p>
  
  <pre>
  Total Physical Memory: 65, 536 MB
  Available Physical Memory: 26,512MB
  Virtual Memory: Max Size 69,630 MB
  Virtual Memory: Available 299 MB
  Virtual Memory: In Use: 69, 331 MB. 
  </pre>
  
  <p>Really just wondering how I go about solving this problem. </p>
  
  <ul>
  <li>Where do I start?</li>
  <li>What does it mean that more virtual memory is being
  used than physical memory, and is this why java won't start? </li>
  <li>Does
  java want to use virtual memory rather than physical memory?</li>
  </ul>
  
  <p><code>java -version</code></p>
  
  <p>gives me:</p>
  
  <p><code>Error occured during initialization of VM
  could not reserve enough space for object heap</code></p>
  
  <p>More specific questions:</p>
  
  <ul>
  <li><strong>Why doesn't the JVM want to use the free phsyical memory?</strong></li>
  <li><strong>How much memory does a java command (like <code>java -version</code>) want to use if you don't specify Xms parameters?</strong></li>
  <li><strong>Would simply assigning more virtual memory be a good solution to the problem?</strong></li>
  </ul>