Is kexec_load supported in RHEL9?

Issue

Introduction:

In the realm of Red Hat Enterprise Linux (RHEL), the landscape of Kexec/Kdump interfaces has undergone significant changes. This knowledgebase article sheds light on the evolution of these interfaces, specifically focusing on the transition from the kexec_load system call to kexec_file_load as the default interface.

Content:

1. Background:

   • In versions prior to RHEL 7, the default interface for loading kexec/kdump kernels was the kexec_load system call.
   • With the advent of RHEL 8, there was a strategic shift towards utilizing the kexec_file_load interface as the default choice.

2. Reasons for Change:

   • The transition to kexec_file_load was motivated by the fact that a substantial portion of its code implementation resides within the Linux kernel.
   • In contrast, kexec_load primarily operates in user space.
   • This shift allows for enhanced manipulation of the kexec/kdump kernel loading process within the kernel itself, aligning with the preference for kernel-side operations.

3. Default Setting:

   • As of RHEL 8, kexec_file_load is the default interface for loading kexec/kdump kernels.
   • This change reflects a strategic decision to leverage the kernel's capabilities in this critical process.

4. Availability of kexec_load:

   • Despite the shift to kexec_file_load, the kexec_load interface is still available.
   • Users have the flexibility to revert to kexec_load if they have specific requirements or preferences.

5. Manual Configuration:

   • Users can manually configure their systems to enable the use of kexec_load if desired.
   • This manual configuration allows for a customized approach based on user needs.

6. Support and Issue Resolution:

   • While kexec_load is not the default, Red Hat acknowledges its presence and provides support for users employing this interface.
   • Issues encountered while using kexec_load will be addressed, although with a lower priority due to the default preference for kexec_file_load.

Conclusion:

Understanding the nuances of the kexec/kdump interfaces in RHEL is crucial for users seeking optimal performance and reliability. While the default choice is kexec_file_load, the availability of kexec_load offers flexibility to users, allowing them to tailor their systems according to their specific requirements. Red Hat remains committed to supporting both interfaces, ensuring a seamless experience for users across diverse use cases.

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