Hi List, I am new to crash / kdump tool and failing some problem as mentioned below. I am referring the Linux Kernel Crash Book (http://www.dedoimedo.com/) and URL http://www.dedoimedo.com/computers/crash.html. I am building modified kernel source (2.6.32 based) and added my modules (for study purpose). Building, installing and booting kernel is successful. I have enabled the options for kdump as mentioned in the book: Enable Kexec system call: CONFIG_KEXEC=y Enable kernel crash dumps: CONFIG_CRASH_DUMP=y Optional: Disable Symmetric Multi-Processing (SMP) support CONFIG_SMP=y Enable sysfs file system support: CONFIG_SYSFS=y Enable /proc/vmcore support: CONFIG_PROC_VMCORE=y Configure the kernel with debug info: CONFIG_DEBUG_INFO=y Configure the start section for reserved RAM for the crash kernel: CONFIG_PHYSICAL_START=0x200000 (2MB) Configure kdump kernel so it can be identified: CONFIG_LOCALVERSION="-crash" Kdump configuration /etc/sysconfig/kdump: KDUMP_KERNELVER="" KDUMP_COMMANDLINE="" KDUMP_COMMANDLINE_APPEND="maxcpus=1 " KEXEC_OPTIONS="" KDUMP_IMMEDIATE_REBOOT="yes" KDUMP_TRANSFER="" KDUMP_SAVEDIR="file:///var/crash" KDUMP_KEEP_OLD_DUMPS="5" KDUMP_FREE_DISK_SIZE="64" KDUMP_VERBOSE="3" KDUMP_DUMPLEVEL="0" KDUMP_DUMPFORMAT="compressed" There is no option KDUMP_DUMPDEV option There is no option KDUMP_RUNLEVEL I booted successfully with this kernel and tried to crash it by module. After rebooting, I found that vmcore is generated under /var/crash/ But I am not able to analyze it with crash command. linux:/home/adil # cat /proc/cmdline root=/dev/disk/by-id/ata-WDC_WD800BD-22LRA1_WD-WMAM9ZS19445-part1 resume=/dev/disk/by-id/ata-WDC_WD800BD-22LRA1_WD-WMAM9ZS19445-part2 splash=silent crashkernel=256M-:128M vga=0x31a linux:/home/adil # linux:/home/adil # crash /boot/System.map-2.6.32.12-crash-crash /boot/vmlinuz-2.6.32.12-crash-crash crash 5.0.1 Copyright (C) 2002-2010 Red Hat, Inc. Copyright (C) 2004, 2005, 2006 IBM Corporation Copyright (C) 1999-2006 Hewlett-Packard Co Copyright (C) 2005, 2006 Fujitsu Limited Copyright (C) 2006, 2007 VA Linux Systems Japan K.K. Copyright (C) 2005 NEC Corporation Copyright (C) 1999, 2002, 2007 Silicon Graphics, Inc. Copyright (C) 1999, 2000, 2001, 2002 Mission Critical Linux, Inc. This program is free software, covered by the GNU General Public License, and you are welcome to change it and/or distribute copies of it under certain conditions. Enter "help copying" to see the conditions. This program has absolutely no warranty. Enter "help warranty" for details. crash: /boot/vmlinuz-2.6.32.12-crash-crash: not a supported file format Usage: crash [-h [opt]][-v][-s][-i file][-d num] [-S] [mapfile] [namelist] [dumpfile] Enter "crash -h" for details. linux:/home/adil # The URL http://www.dedoimedo.com/computers/crash.html mentioned that "The newer versions of Kdump can work with compressed kernel images. Furthermore, they copy the System map file and the kernel image into the crash directory, making the use of crash utility somewhat simpler." linux:/home/adil # ls -al /var/crash/2012-01-30-18\:08/ total 1335536 drwxr-xr-x 2 root root 4096 2012-01-30 18:13 . drwxr-xr-x 8 root root 4096 2012-01-31 12:17 .. -rw-r--r-- 1 root root 187 2012-01-30 18:13 README.txt -rw-r--r-- 1 root root 1716605 2012-01-30 18:13 System.map-2.6.32.12-0.7-default -rw------- 1 root root 1360732590 2012-01-30 18:13 vmcore -rw-r--r-- 1 root root 3774506 2012-01-30 18:13 vmlinux-2.6.32.12-0.7-default.gz linux:/home/adil # ls -al /var/crash/2012-01-31-12\:17/ total 1343860 drwxr-xr-x 2 root root 4096 2012-01-31 12:24 . drwxr-xr-x 8 root root 4096 2012-01-31 12:17 .. -rw-r--r-- 1 root root 187 2012-01-31 12:24 README.txt -rw------- 1 root root 1374748735 2012-01-31 12:24 vmcore linux:/home/adil # linux:/home/adil # ls /boot/ backup_mbr boot boot.readme config-2.6.32.12-0.7-default config-2.6.32.12-0.7-xen grub initrd initrd-2.6.32.12-0.7-default initrd-2.6.32.12-0.7-default-kdump initrd-2.6.32.12-0.7-xen initrd-2.6.32.12-crash-crash initrd-2.6.32.12-crash-crash-kdump initrd-xen message symsets-2.6.32.12-0.7-default.tar.gz symtypes-2.6.32.12-0.7-default.gz symvers-2.6.32.12-0.7-default.gz symvers-2.6.32.12-0.7-xen.gz System.map-2.6.32.12-0.7-default System.map-2.6.32.12-0.7-xen System.map-2.6.32.12-crash-crash vmlinux-2.6.32.12-0.7-xen.gz vmlinuz vmlinuz-2.6.32.12-0.7-default vmlinuz-2.6.32.12-0.7-xen vmlinuz-2.6.32.12-crash-crash vmlinuz-xen vmlinux-2.6.32.12-0.7-default.gz linux:/home/adil # Another observation is boot.kdump seems to on but manually start giving me error: linux:/home/adil # chkconfig boot.kdump boot.kdump on linux:/home/adil # linux:/home/adil # /etc/init.d/boot.kdump start Loading kdump Regenerating kdump initrd ... Can't find kernel text map area from kcore Cannot load /boot/vmlinuz-2.6.32.12-crash-crash failed linux:/home/adil # Other Query: Following is not clear mentioned in the book under "section 11.2 Crash (capture) kernel": -------------- This means that while your production kernels will most likely be named vmlinuz, the Kdump crash kernels need to be uncompressed, hence named vmlinux, or rather vmlinux-kdump. --------------- Please help how to correctly setup and use crash on my machine. Thank you, Adil -- Crash-utility mailing list Crash-utility@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/crash-utility
