centos命令若干

centos删除旧内核

yum -y remove kernel

系统更新 yum – y update && yum -y upgrade

使用cat /boot/grub2/grub.cfg |grep menuentry 查看系统可用内核

[root@bigapp-slave27 ~]# cat /boot/grub2/grub.cfg |grep menuentry
if [ x”${feature_menuentry_id}” = xy ]; then
menuentry_id_option=”–id”
menuentry_id_option=””
export menuentry_id_option
menuentry ‘CentOS Linux (3.10.0-514.16.1.el7.x86_64) 7 (Core)’ –class centos –class gnu-linux –class gnu –class os –unrestricted $menuentry_id_option ‘gnulinux-3.10.0-327.el7.x86_64-advanced-6f5840d0-55ac-4d3b-899b-61c0297c5347’ {
menuentry ‘CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)’ –class centos –class gnu-linux –class gnu –class os –unrestricted $menuentry_id_option ‘gnulinux-3.10.0-327.el7.x86_64-advanced-6f5840d0-55ac-4d3b-899b-61c0297c5347’ {
menuentry ‘CentOS Linux (0-rescue-d57307c454c0437d91c309347178cdf5) 7 (Core)’ –class centos –class gnu-linux –class gnu –class os –unrestricted $menuentry_id_option ‘gnulinux-0-rescue-d57307c454c0437d91c309347178cdf5-advanced-6f5840d0-55ac-4d3b-899b-61c0297c5347’ {

查看当前内核

[root@bigapp-slave27 ~]# uname -r
3.10.0-514.16.1.el7.x86_64

修改开机时默认使用的内核

grub2-set-default ‘CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)’

查看内核修改结果

[root@bigapp-slave27 ~]# grub2-editenv list
saved_entry=CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)

查看系统安装了哪些内核包

[root@bigapp-slave27 ~]# rpm -qa |grep kernel
kernel-3.10.0-327.el7.x86_64
kernel-headers-3.10.0-514.6.1.el7.x86_64
kernel-tools-libs-3.10.0-327.el7.x86_64
kernel-3.10.0-514.16.1.el7.x86_64
kernel-tools-3.10.0-327.el7.x86_64

删除无用内核

yum remove 或rpm -e

yum remove kernel-3.10.0-327.el7.x86_64