| What: /sys/kernel/kexec/* |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: |
| The /sys/kernel/kexec/* directory contains sysfs files |
| that provide information about the configuration status |
| of kexec and kdump. |
| |
| What: /sys/kernel/kexec/loaded |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: read only |
| Indicates whether a new kernel image has been loaded |
| into memory using the kexec system call. It shows 1 if |
| a kexec image is present and ready to boot, or 0 if none |
| is loaded. |
| User: kexec tools, kdump service |
| |
| What: /sys/kernel/kexec/crash_loaded |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: read only |
| Indicates whether a crash (kdump) kernel is currently |
| loaded into memory. It shows 1 if a crash kernel has been |
| successfully loaded for panic handling, or 0 if no crash |
| kernel is present. |
| User: Kexec tools, Kdump service |
| |
| What: /sys/kernel/kexec/crash_size |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: read/write |
| Shows the amount of memory reserved for loading the crash |
| (kdump) kernel. It reports the size, in bytes, of the |
| crash kernel area defined by the crashkernel= parameter. |
| This interface also allows reducing the crashkernel |
| reservation by writing a smaller value, and the reclaimed |
| space is added back to the system RAM. |
| User: Kdump service |
| |
| What: /sys/kernel/kexec/crash_elfcorehdr_size |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: read only |
| Indicates the preferred size of the memory buffer for the |
| ELF core header used by the crash (kdump) kernel. It defines |
| how much space is needed to hold metadata about the crashed |
| system, including CPU and memory information. This information |
| is used by the user space utility kexec to support updating the |
| in-kernel kdump image during hotplug operations. |
| User: Kexec tools |
| |
| What: /sys/kernel/kexec/crash_cma_ranges |
| Date: Nov 2025 |
| Contact: kexec@lists.infradead.org |
| Description: read only |
| Provides information about the memory ranges reserved from |
| the Contiguous Memory Allocator (CMA) area that are allocated |
| to the crash (kdump) kernel. It lists the start and end physical |
| addresses of CMA regions assigned for crashkernel use. |
| User: kdump service |
