Lines Matching +full:configuration +full:- +full:dependent
2 Documentation for Kdump - The kexec-based Crash Dumping Solution
11 Kdump uses kexec to quickly boot to a dump-capture kernel whenever a
14 the reboot and is accessible to the dump-capture kernel.
24 the dump-capture kernel. This ensures that ongoing Direct Memory Access
25 (DMA) from the system kernel does not corrupt the dump-capture kernel.
26 The kexec -p command loads the dump-capture kernel into this reserved
31 region just before rebooting into the dump-capture kernel.
45 passed to the dump-capture kernel through the elfcorehdr= boot
50 With the dump-capture kernel, you can access the memory image through
51 /proc/vmcore. This exports the dump as an ELF-format file that you can
61 Install kexec-tools
62 -------------------
66 2) Download the kexec-tools user-space package from the following URL:
68 http://kernel.org/pub/linux/utils/kernel/kexec/kexec-tools.tar.gz
72 The latest kexec-tools git tree is available at:
74 - git://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
75 - http://www.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git
78 http://www.kernel.org/git/?p=utils/kernel/kexec/kexec-tools.git
80 More information about kexec-tools can be found at
85 tar xvpzf kexec-tools.tar.gz
87 4) Change to the kexec-tools directory, as follows::
89 cd kexec-tools-VERSION
104 Build the system and dump-capture kernels
105 -----------------------------------------
108 1) Build a separate custom dump-capture kernel for capturing the
111 2) Or use the system kernel binary itself as dump-capture kernel and there is
112 no need to build a separate dump-capture kernel. This is possible
122 Following are the configuration setting required for system and
123 dump-capture kernels for enabling kdump support.
126 ----------------------------
132 2) Enable "sysfs file system support" in "Filesystem" -> "Pseudo
152 Dump-capture kernel config options (Arch Independent)
153 -----------------------------------------------------
160 2) Enable "/proc/vmcore support" under "Filesystems" -> "Pseudo filesystems"::
166 Dump-capture kernel config options (Arch Dependent, i386 and x86_64)
167 --------------------------------------------------------------------
178 2) On i386 and x86_64, disable symmetric multi-processing support
184 when loading the dump-capture kernel, see section "Load the Dump-capture
201 kexec boot loader will load it in memory region reserved for dump-capture
206 start of memory region reserved for dump-capture kernel.
211 to the boot loader configuration files.
213 Dump-capture kernel config options (Arch Dependent, ppc64)
214 ----------------------------------------------------------
226 Dump-capture kernel config options (Arch Dependent, ia64)
227 ----------------------------------------------------------
229 - No specific options are required to create a dump-capture kernel
232 as a dump-capture kernel if desired.
248 Dump-capture kernel config options (Arch Dependent, arm)
249 ----------------------------------------------------------
251 - To use a relocatable kernel,
256 Dump-capture kernel config options (Arch Dependent, arm64)
257 ----------------------------------------------------------
259 - Please note that kvm of the dump-capture kernel will not be enabled
260 on non-VHE systems even if it is configured. This is because the CPU
267 configurations, sometimes it's handy to have the reserved memory dependent
268 on the value of System RAM -- that's mostly for distributors that pre-setup
275 range=start-[end]
279 crashkernel=512M-2G:64M,2G-:128M
293 1) Update the boot loader (such as grub, yaboot, or lilo) configuration
297 where Y specifies how much memory to reserve for the dump-capture kernel
300 starting at physical address 0x01000000 (16MB) for the dump-capture kernel.
308 dump-capture kernel config option notes above.
311 On s390x, typically use "crashkernel=xxM". The value of xx is dependent
313 dependent on the memory size of the production system.
322 Load the Dump-capture Kernel
325 After booting to the system kernel, dump-capture kernel needs to be
330 of dump-capture kernel. Following is the summary.
334 - Use vmlinux if kernel is not relocatable.
335 - Use bzImage/vmlinuz if kernel is relocatable.
339 - Use vmlinux
343 - Use vmlinux or vmlinuz.gz
347 - Use image or bzImage
351 - Use zImage
355 - Use vmlinux or Image
358 to load dump-capture kernel::
360 kexec -p <dump-capture-kernel-vmlinux-image> \
361 --initrd=<initrd-for-dump-capture-kernel> --args-linux \
362 --append="root=<root-dev> <arch-specific-options>"
365 to load dump-capture kernel::
367 kexec -p <dump-capture-kernel-bzImage> \
368 --initrd=<initrd-for-dump-capture-kernel> \
369 --append="root=<root-dev> <arch-specific-options>"
372 to load dump-capture kernel::
374 kexec --type zImage -p <dump-capture-kernel-bzImage> \
375 --initrd=<initrd-for-dump-capture-kernel> \
376 --dtb=<dtb-for-dump-capture-kernel> \
377 --append="root=<root-dev> <arch-specific-options>"
380 to load dump-capture kernel::
382 kexec -p <dump-capture-kernel-Image> \
383 --initrd=<initrd-for-dump-capture-kernel> \
384 --append="root=<root-dev> <arch-specific-options>"
386 Please note, that --args-linux does not need to be specified for ia64.
387 It is planned to make this a no-op on that architecture, but for now
391 loading dump-capture kernel.
413 Notes on loading the dump-capture kernel:
418 So, on non-PAE systems, ELF32 is always used.
420 The --elf32-core-headers option can be used to force the generation of ELF32
422 with ELF64 headers on 32-bit systems.
425 due to shared interrupts in the dump-capture kernel.
427 * You must specify <root-dev> in the format corresponding to the root
430 * Boot parameter "1" boots the dump-capture kernel into single-user
434 dump. Hence generally it is useful either to build a UP dump-capture
435 kernel or specify maxcpus=1 option while loading dump-capture kernel.
439 * You should enable multi-cpu support in dump-capture kernel if you intend
440 to use multi-thread programs with it, such as parallel dump feature of
441 makedumpfile. Otherwise, the multi-thread program may have a great
442 performance degradation. To enable multi-cpu support, you should bring up an
443 SMP dump-capture kernel and specify maxcpus/nr_cpus, disable_cpu_apicid=[X]
463 After successfully loading the dump-capture kernel as previously
464 described, the system will reboot into the dump-capture kernel if a
466 die(), die_nmi() and in the sysrq handler (ALT-SysRq-c).
471 will boot into the dump-capture kernel ( die_nmi() ).
475 the system will boot into the dump-capture kernel.
477 On powerpc systems when a soft-reset is generated, die() is called by all cpus
478 and the system will boot into the dump-capture kernel.
480 For testing purposes, you can trigger a crash by using "ALT-SysRq-c",
481 "echo c > /proc/sysrq-trigger" or write a module to force the panic.
486 After the dump-capture kernel is booted, write out the dump file with
489 cp /proc/vmcore <dump-file>
498 /proc/vmcore. Use the debug vmlinux built with -g and run the following
501 gdb vmlinux <dump-file>
508 ELF32-format headers using the --elf32-core-headers kernel option on the
514 https://github.com/crash-utility/crash
517 https://crash-utility.github.io/
533 This will cause a kdump to occur at the add_taint()->panic() call.
538 - Vivek Goyal (vgoyal@redhat.com)
539 - Maneesh Soni (maneesh@in.ibm.com)