960905, 4Fax #2768

Determining Location and Cause of "core" File



Special Notices

Information in this document is correct to the best of our
knowlede at the time of this writing.  Please send feedback
by fax to "AIXServ Information" at (512) 823-4009.

Please use this information with care.  IBM will not be responsible
for damages of any kind resulting from its use. The use of this
information is the sole responsibility of the customer and depends
on the customer's ability to evaluate and integrate this information
into the customer's operational environment.

About This Document

This document describes how to determine where the "core" file
resides and which program caused it. This document is applicable
to AIX versions 3.2.  You should have a core file if you have an
error log entry with the following:

          ERROR LABEL:    CORE_DUMP
          ERROR ID:       0F27AAE5

PROCEDURE

1.  Log in as root.

2.  Run "errpt -a | pg" and look for the word "CORE_DUMP".
    Note the file system Serial Number and the Inode Number from
    the CORE_DUMP error log entry.  Here is an example:

        ERROR LABEL: CORE_DUMP
        ...
        File system Serial Number
               8
        Inode Number
               2049

3.  Run "echo vfs | crash > file".  Then look at the output (in
    "file")to find the file system with the Serial Number found
    in step 2.  It will be in the column labeled "NUMBER".

    Example lines from "file":

    >VFS ADDRESS   TYPE OBJECT    STUB    NUMBER FLAGS   PATHS
      5 583b4f4    jfs  5843108   58436b8      8 D       /dev/hd1 mounted
      over /home

    Note the directory following "mounted over" in the PATHS
    section("/home" in the example above).

4.  Now run the following command, replacing <dir> with the directory
    found in step 3. and replacing <inum> with the Inode Number
    found in step 2:

        find <dir> -xdev -inum <inum> -print

    Here is example output from the "find" command:

        /home/user_name

    The output above is the directory in which the "core"
    file resides.

    An alternate method to locate core files is to use the
    "find" command with the following:

         find / -name core -ls

    then look for a core file with the same date and time as
    the entry in the "errpt".

5.  Now cd to the directory indicated in step 4.

6.  If you are at AIX 3.2 run the following command:

         /usr/sbin/hdf core 730 64

    The program that caused the core dump is listed on the
    "730" line.  For example:

    00000730  6D65646C 65790000 00000000 00000000  |tsm.....|

    If you recognize the program's name as one of your
    applications, you need to give the "core" file to
    your application supplier for further problem determination.

    If the program listed is an AIX command, or if you are
    unsure of its origin, you may wish to work with AIX support
    on this problem.

    A core file is generated when a program tries to do something
    illegal on the system. The usual cause is trying to access
    memory outside the memory assigned to the program by the system.
    Core files are normally caused by a program error or some type
    of data corruption.

    Unless the program that caused the core file is a special debug
    version of the program normally the only useful information in
    the core file is the name of the module or program that caused a
    core dump.

    Examining the errpt -a log will frequently alert you to possible
    problems with the system that may be the cause of the core file.

    For information on support available from the AIX Support Family
    and Program Services (IBM's base support for code-related
    problems), request these faxes from 1-800-IBM-4FAX:

       1537      Overview of AIX Support
       1760      Using Program Services
       2464      The AIX Support Family















































Reader's Comments
Use this form to tell us what you think about this document. If you have
found errors in it, or if you want to
appearance) or make suggestions for improvement, this is the form to
use.
point of sale, or 1-800-CALL-AIX (for information about support
offerings). These services may be billable. Faxes on a variety of
U.S call  415-4539 using a fax machine phone. When you send comments to
IBM, you grant IBM a nonexclusive right to use or distribute your
obligations to you.
Note:  If you have a problem report or item number, supplying that
specific situation.
Problem Report or Item #:
Be sure to print your name and fax number below if you would like a
reply:
Fax Number:
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
_________________________________________________________________________________
END OF DOCUMENT (core.file.32.cmd, 4Fax # 2768)