kk Blog —— 通用基础

date [-d @int|str] [+%s|"+%F %T"]

ubuntu crash

https://www.jianshu.com/p/3c92647140f7

https://help.ubuntu.com/lts/serverguide/kernel-crash-dump.html

自己编译的内核会OOM,需要增大内存

If the dump does not work due to OOM (Out Of Memory) error, then try increasing the amount of reserved memory by editing

/etc/default/grub.d/kdump-tools.cfg

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GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT crashkernel=384M-:256M"

run sudo update-grub and then reboot afterwards, and then test again.


安装

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sudo apt-get install linux-crashdump

重启机器

需要启动下面的服务

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$ service --status-all | grep ' k'
[ + ] kdump-tools
[ + ] kerneloops
[ + ] kexec
[ + ] kexec-load

查看kdump的状态

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$ kdump-config show
DUMP_MODE:        kdump
USE_KDUMP:        1
KDUMP_SYSCTL:     kernel.panic_on_oops=1
KDUMP_COREDIR:    /var/crash
crashkernel addr: 0x21000000
   /var/lib/kdump/vmlinuz: symbolic link to /boot/vmlinuz-4.15.18
kdump initrd: 
   /var/lib/kdump/initrd.img: symbolic link to /var/lib/kdump/initrd.img-4.15.18
current state:    ready to kdump

验证

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echo 1 > /proc/sys/kernel/sysrq
echo c > /proc/sysrq-trigger