Linux Core File Settings

1.
Ulimit-C view the Core File Size configured by the current system
Ulimit-C unlimited: Change the core file size to unlimited.

2.
Change/proc/sys/kernel/core_uses_pid to 1 and set it to the file name that can control the generated core file.
To modify a file, you must use echo "1"
>/Proc/sys/kernel/core_uses_pid

3.
/Proc/sys/kernel/core_pattern can control the core file storage location and file name format
We recommend/home/CORE. % P. % u. % E _ % T. It is best to set the permission for this directory to 777.

4.
/Proc/sys/fs/suid_dumpable some programs will switch users. At that time, the core file cannot be generated normally. In this case, set it to 1
To modify a file, you must use echo "1"
> // Put proc/sys/fs/suid_dumpable

After modifying the file, restart the program. If the program is pulled from another one, restart the program in the following order: 1. Pull the program; 2. Pull the program.

In the user's ~ /. Add ulimit to the bash_profile.
-C unlimited to allow specific users to generate core files
You can set the Core File Size in ulimit-C 1024...
In addition, for the naming rules of the generated core files, files in the following two proc file systems will have an impact on them:
1./proc/sys/kernel/core_uses_pid can be used to control whether PID is added to the file name of the generated core file as an extension.
2./proc/sys/kernel/core_pattern can be used to set the location or file name of the formatted core file,
For example,/corefile/Core-% E-% P-% T will control the generated core file to be stored in the/corefile directory, the generated file name is core-command name-PID-timestamp.

/Home/enip/CORE/Core

/Corefiles/CORE. % P. % E

In Linux, a core file is usually generated when the process exits abnormally. This file is a memory dump file when the process crashes, also known as core dump.

View Linux script Parsing Method: Echo $0

1. Check whether the core is enabled

Log On With see/See

CSH: limit; coredumpsize = 0, indicating that the core is not enabled; otherwise, the core is enabled.

Bash: ulimit-A; pay attention to the red part. If the value is 0, the core is not opened; otherwise, the core is opened.

2. Enable core and set the size.

If it is not enabled, enable it permanently. Log On As A root/user, VI/etc/security/limits. conf, and pay attention to the soft part in red

Temporarily specify the size to log on as the SEE/See user,

CSH: Limit coredumpsize 4096000

Bash: ulimit-C 4096000 is smaller than the size set in/etc/security/limits. conf

Note: These parameters are temporary. Once the active window is closed and opened again, the core size is invalid.

 

3. Core path Configuration

Note: The specified core path has the write permission.

Log On As the SEE/See user,/sbin/sysctl-A | grep core, and view the path of the current core file.

Check the two configuration values kernel. core_pattern and kernel. core_uses_pid.

Kernel. core_pattern: Core File Path

Kernel. core_uses_pid: generate the core file, with the suffix PID 1: belt; 0: No

Temporary path modification (root permission required)

/Sbin/sysctl-W kernel. core_pattern =/CORE. % E. % P

/Sbin/sysctl-W kernel. core_uses_pid = 0

% P-insert PID into filename --- display process number

% U-insert current uid into filename
--- User ID

% G-insert current GID into filename
--- Group ID

% S-insert signal that caused the coredump into the filename
--- Add the signal that causes the core to be generated

% T-insert UNIX time that the coredump occurred into filename
--- Time

% H-insert hostname where the coredump happened into filename
--- Host Name

% E-insert coredumping executable name into filename --- name

Modify the path permanently (root permission is required, and server restart will take effect ):

Modify/etc/sysctl. conf and add two lines:

Kernel. core_pattern =
/CORE. % E. % P

Kernel. core_uses_pid =
0

Settings take effect
Sysctl-P/etc/sysctl. conf

4. Generate core (used for self-testing)

To see/See users, KSh; kill-11 $

5. Positioning and analysis core

GDB container core file

Then: BT

6. Disable Core

Temporarily close:

CSH: Limit coredumpsize 0

Bash: ulimit-C 0

Note: These parameters are temporary. Once the active window is closed and opened again, the core size is invalid.

Permanently close:

1.
Ulimit-C view the Core File Size configured by the current system
Ulimit-C unlimited: Change the core file size to unlimited.

2.
Change/proc/sys/kernel/core_uses_pid to 1 and set it to the file name that can control the generated core file.
To modify a file, you must use echo "1"
>/Proc/sys/kernel/core_uses_pid

3.
/Proc/sys/kernel/core_pattern can control the core file storage location and file name format
We recommend/home/CORE. % P. % u. % E _ % T. It is best to set the permission for this directory to 777.

4.
/Proc/sys/fs/suid_dumpable some programs will switch users. At that time, the core file cannot be generated normally. In this case, set it to 1
To modify a file, you must use echo "1"
> // Put proc/sys/fs/suid_dumpable

After modifying the file, restart the program. If the program is pulled from another one, restart the program in the following order: 1. Pull the program; 2. Pull the program.

In the user's ~ /. Add ulimit to the bash_profile.
-C unlimited to allow specific users to generate core files
You can set the Core File Size in ulimit-C 1024...
In addition, for the naming rules of the generated core files, files in the following two proc file systems will have an impact on them:
1./proc/sys/kernel/core_uses_pid can be used to control whether PID is added to the file name of the generated core file as an extension.
2./proc/sys/kernel/core_pattern can be used to set the location or file name of the formatted core file,
For example,/corefile/Core-% E-% P-% T will control the generated core file to be stored in the/corefile directory, the generated file name is core-command name-PID-timestamp.

/Home/enip/CORE/Core

/Corefiles/CORE. % P. % E

In Linux, a core file is usually generated when the process exits abnormally. This file is a memory dump file when the process crashes, also known as core dump.

View Linux script Parsing Method: Echo $0

1. Check whether the core is enabled

Log On With see/See

CSH: limit; coredumpsize = 0, indicating that the core is not enabled; otherwise, the core is enabled.

Bash: ulimit-A; pay attention to the red part. If the value is 0, the core is not opened; otherwise, the core is opened.

2. Enable core and set the size.

If it is not enabled, enable it permanently. Log On As A roouser, VI/etc/security/limits. conf, and pay attention to the soft part in red

Temporarily specify the size to log on as the SEE/See user,

CSH: Limit coredumpsize 4096000

Bash: ulimit-C 4096000 is smaller than the size set in/etc/security/limits. conf

Note: These parameters are temporary. Once the active window is closed and opened again, the core size is invalid.

 

3. Core path Configuration

Note: The specified core path has the write permission.

Log On As the SEE/See user,/sbin/sysctl-A | grep core, and view the path of the current core file.

Check the two configuration values kernel. core_pattern and kernel. core_uses_pid.

Kernel. core_pattern: Core File Path

Kernel. core_uses_pid: generate the core file, with the suffix PID 1: belt; 0: No

Temporary path modification (root permission required)

/Sbin/sysctl-W kernel. core_pattern =/CORE. % E. % P

/Sbin/sysctl-W kernel. core_uses_pid = 0

% P-insert PID into filename --- display process number

% U-insert current uid into filename
--- User ID

% G-insert current GID into filename
--- Group ID

% S-insert signal that caused the coredump into the filename
--- Add the signal that causes the core to be generated

% T-insert UNIX time that the coredump occurred into filename
--- Time

% H-insert hostname where the coredump happened into filename
--- Host Name

% E-insert coredumping executable name into filename --- name

Modify the path permanently (root permission is required, and server restart will take effect ):

Modify/etc/sysctl. conf and add two lines:

Kernel. core_pattern =
/CORE. % E. % P

Kernel. core_uses_pid =
0

Settings take effect
Sysctl-P/etc/sysctl. conf

4. Generate core (used for self-testing)

To see/See users, KSh; kill-11 $

5. Positioning and analysis core

GDB container core file

Then: BT

6. Disable Core

Temporarily close:

CSH: Limit coredumpsize 0

Bash: ulimit-C 0

Note: These parameters are temporary. Once the active window is closed and opened again, the core size is invalid.

Permanently close: