What does kdump mean in Linux?

kdump is a feature of the Linux kernel that creates crash dumps in the event of a kernel crash. When triggered, kdump exports a memory image (also known as vmcore) that can be analyzed for the purposes of debugging and determining the cause of a crash.

How do I create a kdump?

How to enable Kdump on RHEL 7 and CentOS 7

  1. Step:1 Install ‘kexec-tools’ using yum command.
  2. Step:2 Update the GRUB2 file to Reserve Memory for Kdump kernel.
  3. Step:3.
  4. Step:4 Start and enable kdump service.
  5. Step:5 Now Test Kdump by manually crashing the system.
  6. Step:6 Use ‘crash’ command to analyze and debug crash dumps.

How do you analyze a kdump?

How to use kdump for Linux Kernel Crash Analysis

  1. Install Kdump Tools. First, install the kdump, which is part of kexec-tools package.
  2. Set crashkernel in grub. conf.
  3. Configure Dump Location.
  4. Configure Core Collector.
  5. Restart kdump Services.
  6. Manually Trigger the Core Dump.
  7. View the Core Files.
  8. Kdump analysis using crash.

How do I use kdump?

🔗 How to Use Kdump

  1. First, install the kexec-tools , crash and kernel-debuginfo packages using the following command line.
  2. Fedora 34 and older: Use kdumpctl estimate to determine the recommended crash kernel size to use.
  3. Fedora 35 and newer: Use kdumpctl reset-crashkernel .

How do I read a core dump file in Linux?

In a terminal, run sleep 30 to start a process sleeping for 30 seconds. While it is running, press Ctrl + \ to force a core dump. You’ll now see a core file in the directory you are in.

How do I debug using kdump?

What is kdump redhat?

kdump uses the kexec system call to boot into the second kernel (a capture kernel) without rebooting; and then captures the contents of the crashed kernel’s memory (a crash dump or a vmcore) and saves it into a file.