Difference between revisions of "Enabling Core Files"

(Adding Article Infobox)
Line 18: Line 18:
 
  kernel.core_pattern=/tmp/core
 
  kernel.core_pattern=/tmp/core
 
or for the GNR release and later:
 
or for the GNR release and later:
  kernel.core=/opt/zimbra/data/tmp/core
+
  kernel.core_pattern=/opt/zimbra/data/tmp/core
  
 
This would cause all core files to get created in /tmp/ (or /opt/zimbra/data/tmp/).  Obviously, this can be changed to any other directory as well.  The default is kernel.core_pattern=core, which means it gets created in whatever the current working directory was at the time the process started, which is less useful, as that could be anywhere on the system and may not be writable by the executing process.
 
This would cause all core files to get created in /tmp/ (or /opt/zimbra/data/tmp/).  Obviously, this can be changed to any other directory as well.  The default is kernel.core_pattern=core, which means it gets created in whatever the current working directory was at the time the process started, which is less useful, as that could be anywhere on the system and may not be writable by the executing process.

Revision as of 23:12, 24 August 2010

Admin Article

Article Information

This article applies to the following ZCS versions.

ZCS 6.0 Article ZCS 6.0 ZCS 5.0 Article ZCS 5.0 ZCS 4.5 Article ZCS 4.5

Core Files

Sometimes a bug in a piece of software will cause it to crash, and, if enabled, create a core file. This core file can often be used by Zimbra Technical Support to examine what problem occurred and either fix it, or contact the proper project (OpenLDAP, MySQL, etc) with the details so it can be fixed in their code and incorporated into ZCS. This wiki discusses how to enable core files on Linux and OSX OSes.

Linux

Enabling core files on Linux varies slightly based on kernel revision and distributor. The primary parts are to enable core dumps via sysctl settings. The parameters are:

kernel.core_uses_pid=1

This appends the PID to the generated core file, allowing multiple core dumps.

kernel.suid_dumpable=2
fs.suid_dumpable=2

Depending on the kernel release, one of these two must be set to two. Older 2.6 kernels use the kernel.suid_dumpable parameter (RHEL4, CentOS4, SLES10, OpenSuSE 10.2). Newer ones use fs.suid_dumpable (RHEL5, CentOS5, F7, DEBIAN4.0, UBUNTU6, UBUNTU8). What this parameter does is allow binaries that are setuid (like slapd) to drop core.

Optional (but useful):

kernel.core_pattern=/tmp/core

or for the GNR release and later:

kernel.core_pattern=/opt/zimbra/data/tmp/core

This would cause all core files to get created in /tmp/ (or /opt/zimbra/data/tmp/). Obviously, this can be changed to any other directory as well. The default is kernel.core_pattern=core, which means it gets created in whatever the current working directory was at the time the process started, which is less useful, as that could be anywhere on the system and may not be writable by the executing process.

These parameters should be set in /etc/sysctl.conf. After the modifications are finished, the command

/sbin/sysctl -p /etc/sysctl.conf

can be executed so that a reboot is not necessary (although some OSes require a reboot, see below).

REDHAT derivative OSes only

RedHat derivative OSes (RHEL4, RHEL5, F7, CentOS) also need to have a modification made to the startup scripts. By default, those OSes hard set the coresize to zero in /etc/profile. To fix this, you need to find the following line in /etc/profile:

ulimit -S -c 0 > /dev/null 2>&1

and change it to

ulimit -S -c unlimited > /dev/null 2>&1

and then reboot the system.

OSX derivatives

Core dumps are disabled by default under Darwin/Mac OS X. To re-enable core dumps, a privileged user must edit /etc/hostconfig to contain the line:

COREDUMPS=-YES-
Verified Against: ZCS 4.5.x, 5.0.x, 6.0.x Date Created: 6/16/2009
Article ID: https://wiki.zimbra.com/index.php?title=Enabling_Core_Files Date Modified: 2010-08-24



Try Zimbra

Try Zimbra Collaboration with a 60-day free trial.
Get it now »

Want to get involved?

You can contribute in the Community, Wiki, Code, or development of Zimlets.
Find out more. »

Looking for a Video?

Visit our YouTube channel to get the latest webinars, technology news, product overviews, and so much more.
Go to the YouTube channel »

Jump to: navigation, search