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