Solved

CentOS 6.4 Core files

Posted on 2013-06-30
8
621 Views
Last Modified: 2013-07-03
Hi,

I have installed CentOS 6.4 64bit few days ago and noticed that the hard drive got full within few days. I looked in /tmp folder and noticed lots of core.numbers files ie core.1111 core.32323

These files are being created every few seconds.

ulimit -c shows zero which basically means that no core file should be created.

I would like to know why these files are being created? Apparently I need to know the application that is creating this file before debugging.

And how do I stop these files from being created?


Thanks.
0
Comment
Question by:ezzadin
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 5
  • 3
8 Comments
 
LVL 30

Expert Comment

by:Kerem ERSOY
ID: 39288726
Hi,

Will you post your dmsesg output here?

Cheers,
K.
0
 

Author Comment

by:ezzadin
ID: 39288775
Hi,

Attached is the dmesg.

Thanks.
dmesg.txt
0
 
LVL 30

Expert Comment

by:Kerem ERSOY
ID: 39288784
I did not find anything unusual here. Will you please post :

/etc/sysctl.conf

/var/log/messages
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 30

Expert Comment

by:Kerem ERSOY
ID: 39288785
It seems that your system was configured to generate core dump files for crashes. I think we need to find what is causing crashes.
0
 

Author Comment

by:ezzadin
ID: 39288812
Hi,

here is sysctl:

# Kernel sysctl configuration file for Red Hat Linux
#
# For binary values, 0 is disabled, 1 is enabled.  See sysctl(8) and
# sysctl.conf(5) for more details.

# Controls IP packet forwarding
net.ipv4.ip_forward = 0

# Controls source route verification
net.ipv4.conf.default.rp_filter = 1

# Do not accept source routing
net.ipv4.conf.default.accept_source_route = 0

# Controls the System Request debugging functionality of the kernel
kernel.sysrq = 0

# Controls whether core dumps will append the PID to the core filename.
# Useful for debugging multi-threaded applications.
kernel.core_uses_pid = 1

# Controls the use of TCP syncookies
net.ipv4.tcp_syncookies = 1

# Disable netfilter on bridges.
net.bridge.bridge-nf-call-ip6tables = 0
net.bridge.bridge-nf-call-iptables = 0
net.bridge.bridge-nf-call-arptables = 0

# Controls the default maxmimum size of a mesage queue
kernel.msgmnb = 65536

# Controls the maximum size of a message, in bytes
kernel.msgmax = 65536

# Controls the maximum shared segment size, in bytes
kernel.shmmax = 68719476736

# Controls the maximum number of shared memory segments, in pages
kernel.shmall = 4294967296

Open in new window


I didnt see anything is /var/log/messages.

I rebooted the system few minutes ago and it stopped creating the files...
0
 
LVL 30

Accepted Solution

by:
Kerem ERSOY earned 500 total points
ID: 39289292
In fact you don't have a core file setting in your sysctl file. For your system to create dump files like that you had something different in your sysctl. Something like this:

kernel.core_uses_pid = 1
kernel.core_pattern = /tmp/core-%e-%s-%u-%g-%p-%t
fs.suid_dumpable = 2

Open in new window


But you don't.

There's one thing that comes to my mind that may be you have booted from a different kernel from CD or something which had these settings..

Is it possible that you've reboot from rescue kernel and set your your after boot ??

This is the only thing that I could come up with..

cheers,
K.
0
 

Author Comment

by:ezzadin
ID: 39290027
I actually had this box installed and configured in the office and had is running for few days then shut it down and moved it to our data-center and powered up.

The system started creating the dump file when it was powered up in the data-center, so as you mentioned maybe it just booted from rescue kernel and once the server was rebooted, it started normally.

In any case, thanks for your help.
0
 
LVL 30

Expert Comment

by:Kerem ERSOY
ID: 39298354
You're welcome.
0

Featured Post

What is SQL Server and how does it work?

The purpose of this paper is to provide you background on SQL Server. It’s your self-study guide for learning fundamentals. It includes both the history of SQL and its technical basics. Concepts and definitions will form the solid foundation of your future DBA expertise.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

rdate is a Linux command and the network time protocol for immediate date and time setup from another machine. The clocks are synchronized by entering rdate with the -s switch (command without switch just checks the time but does not set anything). …
It’s 2016. Password authentication should be dead — or at least close to dying. But, unfortunately, it has not traversed Quagga stage yet. Using password authentication is like laundering hotel guest linens with a washboard — it’s Passé.
Learn several ways to interact with files and get file information from the bash shell. ls lists the contents of a directory: Using the -a flag displays hidden files: Using the -l flag formats the output in a long list: The file command gives us mor…
How to Install VMware Tools in Red Hat Enterprise Linux 6.4 (RHEL 6.4) Step-by-Step Tutorial
Suggested Courses

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question