Chapter 10. Installing kdump

In many cases, the kdump service is installed and activated by default on the new Red Hat Enterprise Linux installations. This section includes information about kdump.

10.1. What is kdump

kdump is a service providing a crash dumping mechanism. The service enables you to save the contents of the system’s memory for later analysis. 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. The second kernel resides in a reserved part of the system memory.


A kernel crash dump can be the only information available in the event of a system failure (a critical bug). Therefore, ensuring that kdump is operational is important in mission-critical environments. Red Hat advise that system administrators regularly update and test kexec-tools in your normal kernel update cycle. This is especially important when new kernel features are implemented.