UNIX for Dummies Questions & Answers

Hi

I am using Linux and I am using Java as well as C++ services running on it.
The ulimit -c is set to around 400Mb.
Whenever any of the service fails they produce a core file.(Actual size of core could be greater than 400Mb).
Whenever my Java service fails I get a core file of size 400Mb (Actual size of this core can be more than 8GB.) .But if my C++ service fails I don't get a core file(even though I know there is a core file generated),as it generates a file which tell that a core file is generated.(Java service also generates a file telling a core file is generated).
Could you please advise, is it only because of ulimit -c?

Thanks

Does your C++ service change its uid at some point? Because core file generation is disabled by default for security reasons in that case; writing the value 2 to /proc/sys/fs/suid_dumpable will help then.

We have created a new server using the server of crash .
We reproduce our case here and the core file is getting generated.
The core file size is around 550MB.(ulimit was unlimited)
We still don't know why it is happening on the original server.

We cannot tell from the mere existence of a core file, why the core file was created.

You could load it in gdb, see what caused it to crash. This may be more puzzling than illuminating if it really did crash.

The core is probably a sparse file -- the same length as your computer's address space, but strewn with empty holes which cause the file's actual size on disk to be somewhat smaller. Check it with du.

Code:

ls -lh filename
du -hs filename