1What: /sys/kernel/kexec/* 2Date: Nov 2025 3Contact: kexec@lists.infradead.org 4Description: 5 The /sys/kernel/kexec/* directory contains sysfs files 6 that provide information about the configuration status 7 of kexec and kdump. 8 9What: /sys/kernel/kexec/loaded 10Date: Nov 2025 11Contact: kexec@lists.infradead.org 12Description: read only 13 Indicates whether a new kernel image has been loaded 14 into memory using the kexec system call. It shows 1 if 15 a kexec image is present and ready to boot, or 0 if none 16 is loaded. 17User: kexec tools, kdump service 18 19What: /sys/kernel/kexec/crash_loaded 20Date: Nov 2025 21Contact: kexec@lists.infradead.org 22Description: read only 23 Indicates whether a crash (kdump) kernel is currently 24 loaded into memory. It shows 1 if a crash kernel has been 25 successfully loaded for panic handling, or 0 if no crash 26 kernel is present. 27User: Kexec tools, Kdump service 28 29What: /sys/kernel/kexec/crash_size 30Date: Nov 2025 31Contact: kexec@lists.infradead.org 32Description: read/write 33 Shows the amount of memory reserved for loading the crash 34 (kdump) kernel. It reports the size, in bytes, of the 35 crash kernel area defined by the crashkernel= parameter. 36 This interface also allows reducing the crashkernel 37 reservation by writing a smaller value, and the reclaimed 38 space is added back to the system RAM. 39User: Kdump service 40 41What: /sys/kernel/kexec/crash_elfcorehdr_size 42Date: Nov 2025 43Contact: kexec@lists.infradead.org 44Description: read only 45 Indicates the preferred size of the memory buffer for the 46 ELF core header used by the crash (kdump) kernel. It defines 47 how much space is needed to hold metadata about the crashed 48 system, including CPU and memory information. This information 49 is used by the user space utility kexec to support updating the 50 in-kernel kdump image during hotplug operations. 51User: Kexec tools 52 53What: /sys/kernel/kexec/crash_cma_ranges 54Date: Nov 2025 55Contact: kexec@lists.infradead.org 56Description: read only 57 Provides information about the memory ranges reserved from 58 the Contiguous Memory Allocator (CMA) area that are allocated 59 to the crash (kdump) kernel. It lists the start and end physical 60 addresses of CMA regions assigned for crashkernel use. 61User: kdump service 62