Core files are generated when a process or application terminates abnormally. Core files
are managed with the coreadm command. For example, you can use the coreadm
command to configure a system so that all process core files are placed
in a single system directory. This means it is easier to track problems
by examining the core files in a specific directory whenever a process or
daemon terminates abnormally.
- Configurable Core File Paths
- Expanded Core File Names
- Setting the Core File Name Pattern
- Enabling setuid Programs to Produce Core Files
- Managing Core Files (Task Map)
- Displaying the Current Core Dump Configuration
- How to Set a Core File Name Pattern
- How to Enable a Per-Process Core File Path
- How to Enable a Global Core File Path
- Configurable Core File Paths
- Expanded Core File Names
- Setting the Core File Name Pattern
- Enabling setuid Programs to Produce Core Files
- How to Display the Current Core Dump Configuration
- How to Set a Core File Name Pattern
- How to Display a Core File Name Pattern
- How to Enable a Per-Process Core File Path
- How to Enable a Global Core File Path
- Troubleshooting Core File Problems
- Find and delete all core files in a directory
- How do I make use of core files to find application problems in C/C++?
- Find Core File in multiple machine
- Step by Step Guide on Moving WordPress Core Files to Root Directory
- Setting up Permalinks
- Redirecting Media Files
Configurable Core File Paths
-
A per-process core file path, which defaults to core and is enabled by default. If enabled, the per-process core file path causes a core file to be produced when the process terminates abnormally. The per-process path is inherited by a new process from its parent process.
-
A global core file path, which defaults to core and is disabled by default. If enabled, an additional core file with the same content as the per-process core file is produced by using the global core file path.
When a process terminates abnormally, it produces a core file in the current
directory by default. If the global core file path is enabled, each abnormally
terminating process might produce two files, one in the current working directory, and
one in the global core file location.
By default, a setuid process does not produce core files using either the
global or per-process path.
Expanded Core File Names
For example, if the global core file path is set to:
Setting the Core File Name Pattern
You can set a core file name pattern on a global, zone,
or per-process basis. In addition, you can set per-process defaults that persist across
a system reboot.
# coreadm -i /var/core/core.%f.%p
# coreadm -p /var/core/core.%f.%p $$
The $$ symbols represent a placeholder for the process ID of the currently
running shell. The per-process core file name pattern is inherited by all child
processes.
Enabling setuid Programs to Produce Core Files
-
If the global setuid option is enabled, a global core file path allows all setuid programs on a system to produce core files.
-
If the per-process setuid option is enabled, a per-process core file path allows specific setuid processes to produce core files.
Managing Core Files (Task Map)
Displaying the Current Core Dump Configuration
Use the coreadm command without any options to display the current core dump configuration.
$ coreadm
global core file pattern:
global core file content: default
init core file pattern: core
init core file content: default
global core dumps: disabled
per-process core dumps: enabled
global setid core dumps: disabled
per-process setid core dumps: disabled
global core dump logging: disabled
How to Set a Core File Name Pattern
- Determine whether you want to set a per-process or global core file and
select one of the following:- Set a per-process file name pattern.
$ coreadm -p $HOME/corefiles/%f.%p $$
- Assume the root role.
- Set a global file name pattern.
# coreadm -g /var/corefiles/%f.%p
- Set a per-process file name pattern.
How to Enable a Per-Process Core File Path
- Assume the root role.
- Enable a per-process core file path.
# coreadm -e process
- Display the current process core file path to verify the configuration.
# coreadm $$ 1180: /home/kryten/corefiles/%f.%p
How to Enable a Global Core File Path
- Assume the root role.
- Enable a global core file path.
# coreadm -e global -g /var/core/core.%f.%p
- Display the current process core file path to verify the configuration.
# coreadm global core file pattern: /var/core/core.%f.%p global core file content: default init core file pattern: core init core file content: default global core dumps: enabled per-process core dumps: enabled global setid core dumps: disabled per-process setid core dumps: disabled global core dump logging: disabled
The coreadm command enables you to manage core files. For
example, you can use the coreadm command to configure a system
so that all process core files are placed in a single system directory. This means
it is easier to track problems by examining the core files in a specific directory
whenever a Solaris process or daemon terminates abnormally.
Limitations of the previous Solaris process core dump features are:
-
Process core files are placed in their current
working directory, and thus all Solaris daemons, which typically chdir
to the root (/) directory as part of their initialization, overwrite
each other’s core files. -
Many system daemons, such as statd,
perform setuid operations but do not produce core files in the
event of a problem, for security reasons.
Configurable Core File Paths
Two new configurable core file paths that can be enabled
or disabled independently of each other are:
-
A per-process core file path, which defaults to core
and is enabled by default. If enabled, the per-process core file path causes a core file to be produced when the process terminates abnormally. The per-process
path is inherited by a new process from its parent process. -
A global core file path, which defaults to core and is disabled by default. If enabled, an additional
core file with the same content as the per-process core file is produced by using
the global core file path.
When a process terminates abnormally, it produces a core
file in the current directory as in previous Solaris releases. But if the global core
file path is enabled and set to /corefiles/core, for example,
then each process that expires produce two core files:
one in the current working directory and one in the /corefiles
directory.
By default, the Solaris core paths and core file retention remain the same:
-
A setuid process does not produce core files using
either the global or per-process path. -
The global core file path is disabled.
-
The per-process core file path is enabled.
-
The per-process core file path is set to core.
Expanded Core File Names
For example, if the global core file path is set to:
Setting the Core File Name Pattern
You can set a core file name pattern on a global basis or a per-process basis,
and you can specify whether you want these settings saved across a system reboot.
$ coreadm -i /var/core/core.%f.%p
Global core values are stored in the /etc/coreadm.conf
file, which means these settings are saved across a system reboot.
This coreadm command sets the per-process core file name
pattern for all processes:
$ coreadm -p /var/core/core.%f.%p $$
The $$ symbols represent a placeholder for the process ID
of the currently running shell. The per-process core file name pattern is inherited
by all child processes.
Enabling setuid Programs to Produce
Core Files
-
If the global setuid option is enabled, a global
core file path allows all setuid programs on a system to produce core files. -
If the per-process setuid option is
enable, a per-process core file path allows specific setuid processes
to produce core files.
How to Display the Current Core
Dump Configuration
Use the coreadm command without any options to display the
current core dump configuration.
$ coreadm
global core file pattern: /var/core/core.%f.%p
init core file pattern: core
global core dumps: enabled
per-process core dumps: enabled
global setid core dumps: enabled
per-process setid core dumps: disabled
global core dump logging: disabled
How to Set a Core File Name Pattern
-
-
Set a per-process file name pattern.
# coreadm -p $HOME/corefiles/%f.%p $$
-
Set a global file name pattern.
# coreadm -g /var/corefiles/%f.%p
-
How to Display a Core File Name
Pattern
$ coreadm $$ 278: core.%f.%p
How to Enable a Per-Process
Core File Path
-
Enable a per-process core file path.
-
Display the current process core file path to verify the configuration.
$ coreadm $$ 1180: /home/kryten/corefiles/%f.%p
How to Enable a Global Core File
Path
-
Enable a global core file path.
# coreadm -e global -g /var/core/core.%f.%p
-
Display the current process core file path to verify the configuration.
# coreadm global core file pattern: /var/core/core.%f.%p init core file pattern: core global core dumps: enabled per-process core dumps: enabled global setid core dumps: disabled per-process setid core dumps: disabled global core dump logging: disabled
Troubleshooting Core File Problems
- Error Message
-
NOTICE: 'set allow_setid_core = 1' in /etc/system is obsolete NOTICE: Use the coreadm command instead of 'allow_setid_core'
- Cause
-
You have an obsolete parameter that
allows setuid core files in your /etc/system
file. - Solution
-
Remove allow_setid_core=1 from the /etc/system file. Then use the coreadm command to enable global setuid core file paths.
Core files are quite huge in size and you may want to delete them to save memory
Make sure you don’t delete any folder named core and some other filed named core which not actually a memory/system dump
Solution 1:
After some searching on the internet, I found a nice piece of code to do this. Solution 2:
To delete all files matching to the regex «*.core» you can use:
find supports many filters like:
if you are afraid for files ending with «core» that are not core files you can filter by
file
command piped to some other linux commands.
Solved it ,
i was opening the
core file
like this :
-
gdb core
core-file
-name - file location-of-binary
going this way :
- gdb -c core-file-name location-of-binary
thanks for the help.
If not, try with shell variable
LD_LIBRARY_PATH
to set its path and try again
gdb <executable> core
.
Another option is to edit config
/etc/ld.so.conf
and run ldconfig.
How to view Core file (general), How to view Core file (general) Ask Question Asked 5 years, 9 months ago Modified 3 years, 4 months ago Viewed 8k times 5 0 Scenario (Ubuntu 16.04): I compile and run a C program (with -g, I get the traditional , and then (of
Find and delete all core files in a directory
core files
are generated when a program terminates abnormally. It consists the working memory of the system when the program exits abnormally. You can use a debugger with the
generated core
file to debug the program. The Challenge is:
-
Delete all core files from a directory (
recursive search
). Core files are quite huge in size and you may want to delete them to save memory - Make sure you don’t delete any folder named core and some other filed named core which not actually a memory/system dump
After some searching on the internet, I found a nice piece of code to do this. Drawback is it asks you to recognize the core file to make sure its not some other
file named
core. Source : http://csnbbs.com/
Please post if you have better solutions.
To delete all files matching to the regex «*.core» you can use:
find . -name "*.core" -type f -delete
find supports many filters like:
-size +1000000c # size > 1G
-mtime +3 # older than 3 days
if you are afraid for files ending with «core» that are not core files you can filter by
file
command piped to some other linux commands. for example —
How do I make use of core files to find application problems in C/C++?
I don’t have any idea how I could find the root cause of a C/C++
linux application’s
problem using the core files. I understand that core files are genereated when something unexpected happens to an application. But I don’t know where to start. Can anybody give me a jump start?
Learn to analyze core-dumps from Here. This is where I learnt from. Yes it uses GDB.
«gdb» is the main tool you can use to analyze
Linux core
dumps. Here are several good tutorials:
-
RMS’s GDB tutorial
-
Howto: Debug Crashed Linux Applications Like a Pro
Some generic help:
Install gdb using :
yum install gdb
gdb
start GDB, with no debugging les
gdb program
begin
debugging program
gdb program core
debug coredu
mp core
produced by program
gdb —help
describe command line options
1- First of all find the directory where the corefile is generated.
2- Then use «ls -ltr» command in the directory to find the latest generated corefile.
3- To load the corefile use
gdb binary path of corefile
This will load the corefile.
4- Then you can get the information using «bt» command. For detailed backtrace use «bt full».
5- To print the variables use «print varibale-name» or » p varibale-name»
6- To get any help on gdb use «help» option or use «apropos search-topic»
7- Use «frame frame-number» to go to desired frame number.
8- Use «up n» and «down n» commands to select frame n frames up and select frame n frames down respectively.
9- To stop gdb use «quit» or «q».
Find Core File in multiple machine
I have got the requirement to find the core file in multiple box/machine and trigger email about core
file generation
.
Do we have any utility which help us to find core in single machine or multiple machine.
I believe we should have any utility to find the core file beacuse it is very generic scenario.
After the below input, I am able to write a
Perl script
which find the core file and trigger mail if any core
file exist
This script work fine into local machine but I need to add all Production server. Does anyone also provide me any idea to connect linux terminal through Perl script.
As of now, we are concentrating on dev machine So this script can login into all dev machine and find the core file.
The old-fashioned way is to periodically search the whole filesystem for core files:
find / -type f -name core
find / -type f -name 'core.*'
Fortunately, modern Linux systems are somewhat more configurable. You can use the
/proc/sys/kernel/core_pattern
file to set up a specific directory where core files will be placed, as well as a format for the name of the file. You can have core filenames that contain the name of the program, the UID and GID under which it was launched and so on — have a look at this manual page.
This way you can keep all your core files in a single directory, which has several advantages:
-
You do not risk havi
ng core
files sprinkled all over the filesystem. -
Since all core files are in a single place, it is far more reasonable to poll for new files as needed.
-
If you want immediate action, you can avoid polling by using
inotifywait
or other tools based on
inotify
to monitor the core file directory.
Implement that into your email script:
find / -name core
Or just cronjob it to output all paths to a log.
Of course you can also change «/» in the find command with a specific path
Shell script will better option for your question. I am not used to with shell script but i tried to formulate it.
#list of server to be monitored for core file
serverList="root@server1 root@server2 root@server50"
for server in $serverList
do
#core file
log="/tmp/coreFiles.log"
ssh $server find / -type f -name core >$log
if [ -s $log] then
echo "core files for server $server" | mail -s "Core files found" xyz@abc.com < $log
fi
done
Step by Step Guide on Moving WordPress Core Files to Root Directory
Let’s get in.
1. Login to your blog, goto Settings > General enter the WordPress Address URL (http://www.yourdomain.com/your-directory-here).
2. Click the button save changes.
don’t run your blog for now.
3. Secondly, login to your cpanel > File Manager.
4. If you are using multiple domains using the same hosting account then goto the root directory of the one blog for whom you’re trying to move the WordPress core files into another root directory.
5. Here, make a folder with the same directory which you’ve used in your WordPress Address URL before in the first step.
6. Finally, move all the wp- extension files and folders into the directory which you have just created in the step 5.
8. Save the file index.php and try running your blog now.
Congratulations we’ve done moving the WP core files into another root directory.
Setting up Permalinks
You should be happy that you are using WordPress, it makes a lot more easier to your blog, and don’t let you edit a couple of code.
1. If your blog is using permalinks, then goto Settings > Permalinks and update your permalinks once. This will automatically edit up your .htaccess.
Redirecting Media Files
1. Goto Settings > Update URLs
2. Add this URL as old: http://www.yourdomain.com/wp-content
3. Add this URL as new: http://www.yourdomain.com/your-directory-here/wp-content
4. Save Settings.
Thanks for reading.
10 More Discussions You Might Find Interesting
Tagged:
Discussion started by and has been viewed 3,238 times.
There has been
in this discussion.
The last reply was by .
Discussion started by and has been viewed 11,996 times.
There has been
in this discussion.
The last reply was by .
Tagged: beginners, etc passwd, find -ok
Discussion started by and has been viewed 5,979 times.
The last reply was by .
what are core files?? Can I safely delete them??? Please, help
Discussion started by and has been viewed 10,263 times.
There has been
in this discussion.
The last reply was by .
Discussion started by and has been viewed 3,811 times.
There has been
in this discussion.
The last reply was by .
Tagged:
Discussion started by and has been viewed 20,525 times.
There has been
in this discussion.
The last reply was by .
please help me, what can i do with the bountiful amount of core files our systems seem to have on occassional basis?? how do I analyze it and determine why the core file was dumped by the application that dumped it. the operating systems we use are solaris, DG-UX and linux red hat systems.
Tagged: advanced, ca, core, core files, files, linux
Discussion started by and has been viewed 6,125 times.
There has been
in this discussion.
The last reply was by .
Help me
How can I go about doing this.
also, if you have any idea of other files I can delete and what I can do to improve the performance of a system thats running too slow
Tagged: beginners, learn unix
Discussion started by and has been viewed 16,472 times.
There has been
in this discussion.
The last reply was by .
Discussion started by and has been viewed 14,289 times.
There has been
in this discussion.
The last reply was by .
Tagged: accounting, answer, backup, backups, beginners, ca, case, check, code, contents, core, core files, crashed, delete, disk, disk space, file, files, folder, free, hard, hard disk, ime, las, make, man, man pages, modification, options, poor, question, ram, run, running, save, space, standard, system, system v, time, times, usr, version
Discussion started by and has been viewed 3,663 times.
There has been
in this discussion.
The last reply was by .
Original Post by rgfirefly24
ok i am setting up a script to run daily using crontab. This script will search the root filesystem and delete any and all core files. I have set up this script
BTW this job has to be finished by 1800 hours today. Thank you for all the help you can provide
Original Post by rgfirefly24
try to add the option -prune
find / -name core -prune -exec rm -f {} \;
Original Post by rgfirefly24
ok i tried the code as you have it, however it still comes up saying rm : cannot remove ‘<directory path>’ : is a directory
Original Post by rgfirefly24
to look only for files use: -type f
find / -name core -type f -prune -exec rm -f {} \;
Original Post by rgfirefly24
ok thanks ynixon with the -type f on it the script works perfectly. Next questions is: is there a way to send an output to file of the files that were deleted?
Original Post by rgfirefly24
find / -name core -type f -prune -print
Original Post by rgfirefly24
will that send it to a file or to the printer?
(i know lpr and lp are the print commands; however, i have never used -print before.)
Login or Register
for Dates, Times and to Reply
