Incomplete core dump

leoecco · 07-20-2013, 04:53 PM

I have a c++ application that is crashing. The core is being dumped but it is "incomplete". There is enough space in the hard drive and there is no limit for the size of the core dump file. Any ideas on how to solve this?

Code:

root@ubox:/home/ec/project1# ulimit -a
core file size          (blocks, -c) unlimited
data seg size           (kbytes, -d) unlimited
scheduling priority             (-e) 0
file size               (blocks, -f) unlimited
pending signals                 (-i) 128077
max locked memory       (kbytes, -l) 64
max memory size         (kbytes, -m) unlimited
open files                      (-n) 1024
pipe size            (512 bytes, -p) 8
POSIX message queues     (bytes, -q) 819200
real-time priority              (-r) 0
stack size              (kbytes, -s) 8192
cpu time               (seconds, -t) unlimited
max user processes              (-u) 128077
virtual memory          (kbytes, -v) unlimited
file locks                      (-x) unlimited

root@ubox:/home/ec/project1# gdb main core
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /home/ec/project1/main...done.
BFD: Warning: /home/ec/project1/core is truncated: expected core file size >= 5169152, found: 1114112.
[New LWP 10943]

johnsfine · 07-21-2013, 05:22 AM

I recently had the exact same symptom. In my case the /home directories were mounted via nfs from a file server. I don't really understand the issue. We were able to have files larger than 4GB on that file server, but we were not able to get core dump files larger than 4GB. As you are experiencing, it truncated to a 32-bit file size.

Without understanding the problem, we moved the work to a local partition and redid the operation that crashed and got the full size core dump file.

Our initial, probably incorrect, diagnosis was that the core file was being created in a sub directory of /var before being moved to where it belongs. Some documentation seemed to indicate that, but it was hard to tell which documentation was correct.
We have /var on a very small partition, so first we put in sym links for a few subdirectories of /var to larger partitions (we weren't sure exactly which sub directory of /var was used). When that didn't fix it, we moved the project off of the nfs to a large local partition, but didn't undo the /var changes. So possibly we needed both.