title: Jmap can't connect to make a dump
body: <p>We have an open beta of an app which occasionally causes the heapspace to overflow. The JVM reacts by going on a permanent vacation. </p>
  
  <p>To analyze this I would like to peek into the memory at the point where it failed. Java does not want me to do this. The process is still in memory but it doesn't seem to be recognized as a java process.</p>
  
  <p>The server in question is a debian Lenny server, Java 6u14</p>
  
  <pre><code>/opt/jdk/bin# ./jmap -F -dump:format=b,file=/tmp/apidump.hprof 11175
  Attaching to process ID 11175, please wait...
  sun.jvm.hotspot.debugger.NoSuchSymbolException: Could not find symbol "gHotSpotVMTypeEntryTypeNameOffset" in any of the known library names (libjvm.so, libjvm_g.so, gamma_g)
  at sun.jvm.hotspot.HotSpotTypeDataBase.lookupInProcess(HotSpotTypeDataBase.java:390)
  at sun.jvm.hotspot.HotSpotTypeDataBase.getLongValueFromProcess(HotSpotTypeDataBase.java:371)
  at sun.jvm.hotspot.HotSpotTypeDataBase.readVMTypes(HotSpotTypeDataBase.java:102)
  at sun.jvm.hotspot.HotSpotTypeDataBase.&lt;init&gt;(HotSpotTypeDataBase.java:85)
  at sun.jvm.hotspot.bugspot.BugSpotAgent.setupVM(BugSpotAgent.java:568)
  at sun.jvm.hotspot.bugspot.BugSpotAgent.go(BugSpotAgent.java:494)
  at sun.jvm.hotspot.bugspot.BugSpotAgent.attach(BugSpotAgent.java:332)
  at sun.jvm.hotspot.tools.Tool.start(Tool.java:163)
  at sun.jvm.hotspot.tools.HeapDumper.main(HeapDumper.java:77)
  at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
  at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
  at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
  at java.lang.reflect.Method.invoke(Method.java:597)
  at sun.tools.jmap.JMap.runTool(JMap.java:179)
  at sun.tools.jmap.JMap.main(JMap.java:110)
  Debugger attached successfully.
  sun.jvm.hotspot.tools.HeapDumper requires a java VM process/core!
  </code></pre>