centos-kudump使用

1、安装kexec-tools

[[email protected]_0_11_centos ~]# yum -y install kexec-tools
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * elrepo: mirrors.tuna.tsinghua.edu.cn
Package kexec-tools-2.0.15-33.el7.x86_64 already installed and latest version
Nothing to do

 2、配置kdump

1）修改grub文件

crashkernel=128M，配置保留的内存空间为128M
[[email protected]_0_11_centos ~]# cat /etc/default/grub 
GRUB_TIMEOUT=20
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=1
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL="serial console"
GRUB_TERMINAL_OUTPUT="serial console"
GRUB_CMDLINE_LINUX="crashkernel=128M console=ttyS0 console=tty0 panic=5 net.ifnames=0 biosdevname=0"
GRUB_DISABLE_RECOVERY="true"
GRUB_SERIAL_COMMAND="serial --speed=9600 --unit=0 --word=8 --parity=no --stop=1"

2）生成grub配置文件 

只要更改了gurb文件，都需要更改grub配置
[[email protected]_0_11_centos ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.4.2-1.el7.elrepo.x86_64
Found initrd image: /boot/initramfs-5.4.2-1.el7.elrepo.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-1062.9.1.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-1062.9.1.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-957.21.3.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-957.21.3.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-0ea734564f9a4e2881b866b82d679dfc
Found initrd image: /boot/initramfs-0-rescue-0ea734564f9a4e2881b866b82d679dfc.img
done

3、模拟kdump

1）core文件

默认core文件存放在/var/crash目录下

配置文件/etc/kdump.conf

#raw /dev/vg/lv_kdump
#ext4 /dev/vg/lv_kdump
#ext4 LABEL=/boot
#ext4 UUID=03138356-5e61-4ab3-b58e-27507ac41937
#nfs my.server.com:/export/tmp
#ssh [email protected]
#sshkey /root/.ssh/kdump_id_rsa
path /var/crash
core_collector makedumpfile -l --message-level 1 -d 31
#core_collector scp
#kdump_post /var/crash/scripts/kdump-post.sh
#kdump_pre /var/crash/scripts/kdump-pre.sh
#extra_bins /usr/bin/lftp
#extra_modules gfs2
#default shell

2）设置为开机自启

[[email protected]_0_11_centos ~]# systemctl enable kdump
[[email protected]_0_11_centos ~]# systemctl status kdump
● kdump.service - Crash recovery kernel arming
   Loaded: loaded (/usr/lib/systemd/system/kdump.service; enabled; vendor preset: enabled)
   Active: active (exited) since Wed 2019-12-11 23:44:40 CST; 1 day 23h ago
 Main PID: 1180 (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/kdump.service

Dec 11 23:44:35 VM_0_11_centos systemd[1]: Starting Crash recovery kernel arming...
Dec 11 23:44:40 VM_0_11_centos kdumpctl[1180]: kexec: loaded kdump kernel
Dec 11 23:44:40 VM_0_11_centos kdumpctl[1180]: Starting kdump: [OK]
Dec 11 23:44:40 VM_0_11_centos systemd[1]: Started Crash recovery kernel arming.

3）重启

reboot

4、生成core文件

1）生成core文件

echo c > /proc/sysrq-trigger

2）查看生成的core文件

[[email protected]_0_11_centos ~]# ll /var/crash
total 4
drwxr-xr-x 2 root root 4096 Dec 13 23:32 127.0.0.1-2019-12-13-23:32:35