title: heapdump size vs hprof size
body: <p>I recently made a heapdump in a hprof format when my jboss server was running with a xms of 4096m and xmx of 4096m and a permsize of 512m.</p>
  
  <p>The hprof file generated is over 5gb. When I load the heapdump in visualvm, mat analyzer or yourkit, I only see a total bytes of approximately 1gb. I've tried changed the reachability scope in yourkit but it does not show more than 1 gb.</p>
  
  <p>Any idea what this big difference in filesize vs displayed heapdump size can cause?</p>
  
  <p>ps: I'm using jdk1.6.0_23</p>
  
  <p>Unfortunately I'm not allowed to submit screenshots here.</p>
  
  <p>On the filesystem the hprof size is of 5.227.659 kb and in yourkit it states:</p>
  
  <p>Objects: 9.738.282 / shallow size 740 mb / retained size: 740 mb String reachable among them: 6.652.515 (68%) / shallow size: 381 mb (51%) / retained size: 381 MB (51%)</p>
  
  <p>The largest retained size is a byte[] of 206.810.176</p>