title: Why core file is more than virtual memory?
body: <p>I have a multithreaded program running which crashes after a day or two. Moreover the gdb backtrace of the core dump does not lead anywhere. There are no symbols at the point where it crashes.</p>
  
  <p>Now the machine that generates the core file has a physical memory of 3 Gigs and 5 Gigs swap space. But the core dump that we get is around 25 Gigs. Isn't the core dump actually memory dump? Why is the core dump large?</p>
  
  <p>And can anyone give me more lead on how to debug in such situation?</p>