When I run kill -11 pid, no core file got dumped

Question

I checked the ulimit so it shouldn't be a problem ulimit -c unlimited

What else can I check?

Answer 1

If you are getting no coredump, there are a few possibilities.

1. ulimit : are you sure that the process has core unlimited? Your shell may, but what started the process?

2. Directory permissions : The coredump would be in the cwd. If the process does not have write permission to the cwd then it cannot dump the core.

3. SELinux can apparently cause issues. Check /var/log/messages for warnings if you are on a Linux box and have it enabled.

4. Does your process have some traphandler or a wrapper that is preventing a coredump? (Note that SIGSEGV cannot be trapped but a wrapper process might catch it)

My guess is #2, though you've not given us much in the way of details to work with.