This document describes how to determine where the core file resides and which program caused it. A core file is generated when a program tries to do something illegal on the system. The usual cause is an attempt to access memory outside the memory assigned to the program by the system. Core files are usually caused by a program error or some type of data corruption.
This document applies to AIX Version 4.x only.
If a core file has been created on your system, there should be an error log entry similar to the following:
LABEL: CORE_DUMP IDENTIFIER: DE0A8DC4 Date/Time: Mon Nov 18 08:15:21 Sequence Number: 99 Machine Id: 000003264700 Node Id: katmai Class: S Type: PERM Resource Name: SYSPROC Description SOFTWARE PROGRAM ABNORMALLY TERMINATED Probable Causes SOFTWARE PROGRAM User Causes USER GENERATED SIGNAL Recommended Actions CORRECT THEN RETRY
Failure Causes SOFTWARE PROGRAM Recommended Actions RERUN THE APPLICATION PROGRAM IF PROBLEM PERSISTS THEN DO THE FOLLOWING CONTACT APPROPRIATE SERVICE REPRESENTATIVE Detail Data SIGNAL NUMBER 11 USER'S PROCESS ID: 24010 FILE SYSTEM SERIAL NUMBER 5 INODE NUMBER 2 PROGRAM NAME sleep
In the preceding error log entry, notice that the program that dropped the core file is listed under PROGRAM NAME. In this example it is the sleep command.
find / -name core -ls
lquerypv -h core 6b0 64
The program that caused the core dump is listed on the 6E0 line. For example:
000006B0 7FFFFFFF FFFFFFFF 7FFFFFFF FFFFFFFF |.............| 000006C0 7FFFFFFF FFFFFFFF 7FFFFFFF FFFFFFFF |.............| 000006D0 00120000 13106060 00000000 00000003 |......''.....| 000006E0 736C6565 70000000 00000000 00000000 |sleep........| 000006F0 00000000 00000000 00000000 00000000 |.............| 00000700 00000000 00000000 00000000 00000018 |.............| 00000710 00000000 00000001 00000000 00000012 |.............|
The program that caused the core dump will be listed at the right-hand side of the line, between vertical bars (pipe symbols). In the preceding example the core file shows the sleep program. Depending on the version of AIX, the program name may be on any of the seven lines displayed.
If you recognize the program's name as one of your applications, give the core file to your application supplier for further problem determination.
If the program listed is an AIX command, or if its origin is uncertain, contact AIX Support for this problem.
Run dbx on the binary executable that caused the core dump. This will display the offending system call. In the following example the program that caused the core dump is sleep. Running dbx against the sleep command shows that the offending system call was sleep. AIX Support personnel may ask for this information in some cases.
dbx /usr/bin/sleep core Type 'help' for help. reading symbolic information ...warning: no source compiled with -g [using memory image in core] Segmentation fault in sleep at 0xd0019cd8 0xd0019cd8 (sleep+0x40) 80410014 1 r2,0x14(rl) (dbx) where sleep(??) at 0xd0019cd8 main(??, ??) at 0x10000378 (dbx) quit
If AIX Support personnel determines that the core dump should be sent in to the support center, then also send the output of the snap -g command. This gathers the output of the lslpp -hBc command, which is required to recreate exact operating system environments.
Unless the program that caused the core file is a special debug version of the program, usually the only useful information in the core file is the name of the module or program that caused the core dump.
Examining the errpt -a log frequently alerts you to possible problems with the system that may be the cause of the core file.
[ Doc Ref: 90605199514602 Publish Date: Jul. 26, 2000 4FAX Ref: 6834 ]