Enabling Automatic Kernel Crash Collection with kdump

How to automatically enable and configure kdump crash collection on Linux systems using the kdump-enabler script.

Tags:

Automatic Enablement of Kernel Crash Dump Collection with kdump-enabler

This article explains how to automatically enable and configure kernel crash dump (kdump) collection on Linux systems using the kdump-enabler script. This approach works across multiple distributions and simplifies the process of preparing your system to collect crash dumps for troubleshooting and analysis.

Overview

kdump-enabler is a Bash script that automates the setup of kdump:

Installs required packages
Configures the crashkernel parameter in GRUB
Enables and starts the kdump service
Sets up SysRq for manual crash triggering
Creates backups of configuration files before changes
Supports Ubuntu, Debian, RHEL, CentOS, Fedora, openSUSE, Arch Linux, and more

Prerequisites

Root privileges (run with sudo)
systemd-based Linux distribution
GRUB bootloader
Sufficient disk space in /var/crash for crash dumps

Installation

Clone the repository and run the script:

git clone https://github.com/samatild/kdump-enabler.git
cd kdump-enabler
sudo ./kdump-enabler.sh

Or download and run directly:

curl -O https://raw.githubusercontent.com/samatild/kdump-enabler/main/kdump-enabler.sh
chmod +x kdump-enabler.sh
sudo ./kdump-enabler.sh

Usage

Run the script interactively:

sudo ./kdump-enabler.sh

Or use options for automation:

sudo ./kdump-enabler.sh -y           # Non-interactive mode
sudo ./kdump-enabler.sh --check-only  # Only check current configuration
sudo ./kdump-enabler.sh --no-sysrq    # Skip SysRq crash enablement

What the Script Does

Detects your Linux distribution and package manager
Checks current kdump status
Installs required packages
Configures crashkernel parameter in GRUB based on system RAM
Enables kdump service at boot and starts it
Enables SysRq for manual crash triggering
Creates crash dump directory at /var/crash

Post-Installation

After running the script, reboot your system for the crashkernel parameter to take effect:

sudo reboot

Verify kdump is working:

Ubuntu/Debian:

sudo kdump-tools test
sudo systemctl status kdump-tools

RHEL/CentOS/Fedora:

sudo kdumpctl showmem
sudo systemctl status kdump

Check crashkernel:
```
cat /proc/cmdline | grep crashkernel
```

Check SysRq:

cat /proc/sys/kernel/sysrq
# Should output: 1

Examples

Below are examples of running the script on different distributions and with various options, along with the kinds of output you can expect.

Interactive run (Ubuntu/Debian)

sudo ./kdump-enabler.sh

# Output (abridged):
╔══════════════════════════════════════════════════════════════╗
║                        KDUMP ENABLER v1.0.0                  ║
╚══════════════════════════════════════════════════════════════╝
[INFO] Detecting Linux distribution...
[SUCCESS] Detected: Ubuntu 22.04
[INFO] Package manager: apt

[INFO] Checking current kdump configuration...
[WARNING] No crashkernel parameter found in kernel command line
[WARNING] kdump service exists but is not active
[WARNING] System requires kdump configuration

[WARNING] This script will:
  1. Install kdump packages (linux-crashdump kdump-tools kexec-tools)
  2. Configure crashkernel parameter in GRUB
  3. Enable and start kdump service
  4. Enable SysRq crash trigger
  5. Require a system reboot to complete setup
Do you want to continue? [y/N] y

[INFO] Installing required packages...
... apt-get update -qq
... apt-get install -y linux-crashdump kdump-tools kexec-tools
[SUCCESS] Packages installed successfully

[INFO] Configuring crashkernel parameter...
[INFO] Recommended crashkernel size: 384M (Total RAM: 12GB)
... updating /etc/default/grub
... running update-grub
[SUCCESS] GRUB configuration updated

[INFO] Configuring kdump settings...
... setting USE_KDUMP=1 in /etc/default/kdump-tools
[SUCCESS] kdump-tools configured

[INFO] Enabling kdump service...
[SUCCESS] kdump service enabled at boot
[WARNING] kdump service will start after reboot (crashkernel parameter needs to be loaded)

[INFO] Enabling SysRq crash trigger...
[SUCCESS] SysRq enabled for current session
[SUCCESS] SysRq configuration persisted to /etc/sysctl.conf

╔════════════════════════════════════════════════════════════════╗
║                    KDUMP SETUP COMPLETED                        ║
╚════════════════════════════════════════════════════════════════╝
IMPORTANT: A system reboot is required to apply all changes!

Non-interactive run (auto-confirm)

sudo ./kdump-enabler.sh -y

# Output differences:
# - Skips confirmation prompts
# - Performs install/configuration immediately

Check-only mode (no changes)

sudo ./kdump-enabler.sh --check-only

# Output (abridged):
[INFO] Checking current kdump configuration...
[WARNING] No crashkernel parameter found in kernel command line
[WARNING] kdump service not found
[INFO] Crash dump directory: /var/crash (0 dumps found)

# Exits after status check without installing or modifying anything

Skip SysRq enablement

sudo ./kdump-enabler.sh -y --no-sysrq

# Output differences:
# - Does not enable SysRq or persist sysctl settings
# - All other steps (packages, GRUB, service) proceed

RHEL/Fedora example highlights

sudo ./kdump-enabler.sh -y

# Output (abridged):
[SUCCESS] Detected: Red Hat Enterprise Linux 9
[INFO] Package manager: yum

[INFO] Installing required packages...
... yum install -y kexec-tools
[SUCCESS] Packages installed successfully

[INFO] Configuring crashkernel parameter...
... updating /etc/default/grub
... grub2-mkconfig -o /boot/grub2/grub.cfg
[SUCCESS] GRUB2 configuration updated

[INFO] Configuring kdump settings...
... ensuring path /var/crash in /etc/kdump.conf
... setting core_collector makedumpfile -l --message-level 1 -d 31
[SUCCESS] kdump.conf configured