What is a good way to dump a Linux core file from inside a process?

Question

We have a server (written in C and C++) that currently catches a SEGV and dumps some internal info to a file. I would like to generate a core file and write it to disk at th

Answer 1

I saw pmbrett's post and thought "hey, thats cool" but couldn't find that utility anywhere on my system ( Gentoo ).

So I did a bit of prodding, and discovered GDB has this option in it.

gdb --pid=4049 --batch -ex gcore

Seemed to work fine for me.

Its not however very useful because it traps the very lowest function that was in use at the time, but it still does a good job outside that ( With no memory limitations, Dumped 350M snapshot of a firefox process with it )

Answer 2

Some possible solutions^W ways of dealing with this situation:

1. Fix the ulimit!!!
2. Accept that you don't get a core file and run inside gdb, scripted to do a "thread all apply bt" on SIGSEGV
3. Accept that you don't get a core file and acquired a stack trace from within the application. The Stack Backtracing Inside Your Program article is pretty old but it should be possible these days too.