MAKEDUMPFILE(8) Linux System Administrator's Manual MAKEDUMPFILE(8) (NAME) makedumpfile - kdump (SYNOPSIS) makedumpfile [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE makedumpfile -F [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE makedumpfile [OPTION] -x VMLINUX [--config FILTERCONFIGFILE] [--eppic EPPICMACRO] VMCORE DUMPFILE makedumpfile -R DUMPFILE makedumpfile --split [OPTION] [-x VMLINUX|-i VMCOREINFO] VMCORE DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..] makedumpfile [OPTION] [-x VMLINUX|-i VMCOREINFO] --num-threads THREADNUM VMCORE DUMPFILE makedumpfile --reassemble DUMPFILE1 DUMPFILE2 [DUMPFILE3 ..] DUMPFILE makedumpfile -g VMCOREINFO -x VMLINUX makedumpfile [OPTION] [--xen-syms XEN-SYMS|--xen-vmcoreinfo VMCOREINFO] VMCORE DUMPFILE makedumpfile --dump-dmesg [--partial-dmesg] [-x VMLINUX|-i VMCOREINFO] VMCORE LOGFILE makedumpfile [OPTION] -x VMLINUX --diskset=VMCORE1 --diskset=VMCORE2 [--diskset=VMCORE3 ..] DUMPFILE makedumpfile -h makedumpfile -v (DESCRIPTION) kdump ( "panicked kernel") ( "kdump kernel" "capture kernel") /proc/vmcore . /proc/vmcore VMCORE . makedumpfile DUMPFILE . makedumpfile . VMLINUX VMCOREINFO . makedumpfile VMCORE DUMPFILE : - - () (non-private cache) - () (private cache) - - (Free pages) makedumpfile DUMPFILE ( ELF kdump kdump-compressed). makedumpfile kdump-compressed . crash ELF . ELF GDB crash . GDB DUMPFILE ELF . makedumpfile . / erase . makedumpfile . 'X' ( ) (poison) . makedumpfile.conf(5) . Eppic . Eppic C . --eppic eppic eppic_makedumpfile.so . eppic_makedumpfile.so makedumpfile . eppic libeppic.a eppic . : Rust . makedumpfile VMLINUX VMCOREINFO . VMCOREINFO ( ) initrd . initrd makedumpfile VMLINUX initrd VMLINUX . makedumpfile VMCOREINFO VMLINUX VMCOREINFO . 2.6.24 VMCORE VMCOREINFO -x -i . initrd . SSH makedumpfile ( flattened format) . SSH . ( crash 5.1.2 GDB) makedumpfile ( makedumpfile-R.pl) DUMPFILE . makedumpfile VMCORE DUMPFILE kdump-compressed . DUMPFILE ftp/scp ( dump_level DUMPFILE DUMPFILE ). makedumpfile DUMPFILE dump_level dump_level : : # makedumpfile -c -d 3 /proc/vmcore dumpfile.1 # makedumpfile -c -d 31 dumpfile.1 dumpfile.2 makedumpfile VMCORE sadump : (diskset) kdump-compressed . VMCORE sadump VMLINUX -x . VMCORE --diskset . (OPTIONS) -c,-l,-p,-z : -c : zlib -l : lzo -p : snappy -z : zstd ( -l -p -z makedumpfile USELZO=on USESNAPPY=on USEZSTD=on ). -E ELF . : # makedumpfile -c -d 31 -x vmlinux /proc/vmcore dumpfile -d dump_level . DUMPFILE . . dump_level . dump_level . dump_level Xen x86_64 . x86_64 vmlinux domain-0 -x domain-0 . dump_level ',' '-L' "No space on device" makedumpfile dump_level . dump_level "11,31" makedumpfile dump_level 11 dump_level 31 . : # makedumpfile -d 11 -x vmlinux /proc/vmcore dumpfile # makedumpfile -d 11,31 -x vmlinux /proc/vmcore dumpfile : dump_level : 1 : . 2 : (non-private). 4 : . 8 : . 16 : (free pages). : | |non- | | | dump | zero |private|private| user | free level | page |cache |cache | data | page -------+------+-------+-------+------+------ 0 | | | | | 1 | X | | | | 2 | | X | | | 3 | X | X | | | 4 | | X | X | | 5 | X | X | X | | 6 | | X | X | | 7 | X | X | X | | 8 | | | | X | 9 | X | | | X | 10 | | X | | X | 11 | X | X | | X | 12 | | X | X | X | 13 | X | X | X | X | 14 | | X | X | X | 15 | X | X | X | X | 16 | | | | | X 17 | X | | | | X 18 | | X | | | X 19 | X | X | | | X 20 | | X | X | | X 21 | X | X | X | | X 22 | | X | X | | X 23 | X | X | X | | X 24 | | | | X | X 25 | X | | | X | X 26 | | X | | X | X 27 | X | X | | X | X 28 | | X | X | X | X 29 | X | X | X | X | X 30 | | X | X | X | X 31 | X | X | X | X | X -L SIZE SIZE . SIZE DUMPFILE LOGFILE . -E DUMPFILE ELF. -c -l -p ELF . : # makedumpfile -E -d 31 -x vmlinux /proc/vmcore dumpfile -f mem-usage . : # makedumpfile -f -d 31 -x vmlinux /proc/vmcore dumpfile DUMPFILE . # makedumpfile -f --mem-usage /proc/kcore v4.11 464920104bf7 --mem-usage -f . -x VMLINUX VMLINUX . VMCORE VMCOREINFO [-i VMCOREINFO] dump_level . . : # makedumpfile -d 31 -x vmlinux /proc/vmcore dumpfile -i VMCOREINFO VMCOREINFO VMLINUX . VMCOREINFO makedumpfile -g . VMCORE VMCOREINFO [-x VMLINUX] dump_level . : # makedumpfile -d 31 -i vmcoreinfo /proc/vmcore dumpfile -g VMCOREINFO VMCOREINFO VMLINUX . VMCOREINFO . -i VMCOREINFO . [-x VMLINUX] . : # makedumpfile -g vmcoreinfo -x vmlinux --config FILTERCONFIGFILE -x VMLINUX FILTERCONFIGFILE erase vmcore DUMPFILE . makedumpfile.conf(5) . --eppic EPPICMACRO -x VMLINUX eppic eppic vmcore DUMPFILE . eppic . -F (flattened format) SSH. ( crash 5.1.2 GDB) . -R DUMPFILE ( ) . -F . -R . -E -F ELF kdump-compressed . -F . : # makedumpfile -F -c -d 31 -x vmlinux /proc/vmcore \ | ssh user@host "cat > dumpfile.tmp" # makedumpfile -F -c -d 31 -x vmlinux /proc/vmcore \ | ssh user@host "makedumpfile -R dumpfile" # makedumpfile -F -E -d 31 -i vmcoreinfo /proc/vmcore \ | ssh user@host "makedumpfile -R dumpfile" # makedumpfile -F -E --xen-vmcoreinfo VMCOREINFO /proc/vmcore \ | ssh user@host "makedumpfile -R dumpfile" -R DUMPFILE ( ). : # makedumpfile -R dumpfile < dumpfile.tmp # makedumpfile -F -d 31 -x vmlinux /proc/vmcore \ | ssh user@host "makedumpfile -R dumpfile" -R "makedumpfile-R.pl" DUMPFILE . perl . makedumpfile . : # makedumpfile -F -d 31 -x vmlinux /proc/vmcore \ | ssh user@host "makedumpfile-R.pl dumpfile" --split DUMPFILE. / . . kdump-compressed . : # makedumpfile --split -d 31 -x vmlinux /proc/vmcore dumpfile1 dumpfile2 --num-threads THREADNUM (thread) DUMPFILE . . DUMPFILE kdump-compressed VMCORE kdump-compressed elf . : # makedumpfile -d 31 --num-threads 4 /proc/vmcore dumpfile --reassemble DUMPFILE --split DUMPFILE . dumpfile1 dumpfile2 dumpfile : : # makedumpfile --reassemble dumpfile1 dumpfile2 dumpfile -b 2^order DUMPFILE . . --cyclic-buffer buffer_size (bitmap). : num_of_cycles = system_memory / (buffer_size * 1024 * bit_per_bytes * page_size ) . buffer_size . : # makedumpfile --cyclic-buffer 1024 -d 31 -x vmlinux /proc/vmcore dumpfile --splitblock-size splitblock_size --split. --splitblock N N . : # makedumpfile --splitblock-size 1024 -d 31 -x vmlinux --split /proc/vmcore dumpfile1 dumpfile2 --work-dir . . . : # makedumpfile --work-dir /tmp -d 31 -x vmlinux /proc/vmcore dumpfile --non-mmap mmap(2) VMCORE . mmap(2) . . : # makedumpfile --non-mmap -d 31 -x vmlinux /proc/vmcore dumpfile --xen-syms XEN-SYMS XEN-SYMS xen. xen domain-0 . : # makedumpfile -E --xen-syms xen-syms /proc/vmcore dumpfile --xen-vmcoreinfo VMCOREINFO VMCOREINFO XEN-SYMS xen. VMCOREINFO makedumpfile -g xen . : # makedumpfile -E --xen-vmcoreinfo VMCOREINFO /proc/vmcore dumpfile -X VMCORE Xen kdump xen domain-0. VMCORE VMCOREINFO Xen --xen-syms --xen-vmcoreinfo . : # makedumpfile -E -X /proc/vmcore dumpfile --xen_phys_start xen_phys_start_address x86_64 . / xen (relocatable) VMCORE xen_phys_start_address CRASHINFO . "Hypervisor code and data" /proc/iomem . /proc/iomem 0xcee00000 : ------------------------------------------------------- # cat /proc/iomem ... cee00000-cfd99999 : Hypervisor code and data ... ------------------------------------------------------- : # makedumpfile -E -X --xen_phys_start 0xcee00000 /proc/vmcore dumpfile --message-level message_level . message_level . X . . message_level . message | progress | common | error | debug | report level | indicator| message | message | message | message ---------+----------+---------+---------+---------+--------- 0 | | | | | 1 | X | | | | 2 | | X | | | 3 | X | X | | | 4 | | | X | | 5 | X | | X | | 6 | | X | X | | * 7 | X | X | X | | 8 | | | | X | 9 | X | | | X | 10 | | X | | X | 11 | X | X | | X | 12 | | | X | X | 13 | X | | X | X | 14 | | X | X | X | 15 | X | X | X | X | 16 | | | | | X 17 | X | | | | X 18 | | X | | | X 19 | X | X | | | X 20 | | | X | | X 21 | X | | X | | X 22 | | X | X | | X 23 | X | X | X | | X 24 | | | | X | X 25 | X | | | X | X 26 | | X | | X | X 27 | X | X | | X | X 28 | | | X | X | X 29 | X | | X | X | X 30 | | X | X | X | X 31 | X | X | X | X | X --vtop virtual_address . virtual_address "vtop" crash . . --dump-dmesg makedumpfile . VMCORE dmesg VMCORE LOGFILE . VMCORE VMCOREINFO dmesg [-x VMLINUX] [-i VMCOREINFO] . : # makedumpfile --dump-dmesg /proc/vmcore dmesgfile # makedumpfile --dump-dmesg -x vmlinux /proc/vmcore dmesgfile --partial-dmesg --dump-dmesg dmesg ( "dmesg --clear") . --mem-usage x86_64 arm64 ppc64 s390x . . dump_level . 'System Ram' 'kernel text' /proc/kcore crashkernel vmcoreinfo /proc/kcore . : # makedumpfile --mem-usage /proc/kcore --diskset=VMCORE VMCORE sadump diskset VMCORE . DUMPFILE . : # makedumpfile -x vmlinux --diskset=vmcore1 --diskset=vmcore2 dumpfile -D . -h (--help) LZO/snappy (/). -v makedumpfile. --check-params . . --dry-run . --dump-dmesg --reassemble -g . --show-stats (report). --message-level . (ENVIRONMENT VARIABLES) TMPDIR . tmpfs /tmp makedumpfile . --work-dir . (DIAGNOSTICS) makedumpfile : 0 : makedumpfile . 1 : makedumpfile . 2 : VMLINUX VMCORE. (AUTHORS) Masaki Tachibana Ken'ichi Ohmichi. (SEE ALSO) crash(8), gdb(1), kexec(8), makedumpfile.conf(5) makedumpfile v1.7.9 20 Apr 2026 MAKEDUMPFILE(8)