概述

安装完成CentOS 7 后，如果使用yum update对系统进行更新，系统也会升级内核版本。

查看当前系统的内核

#uname -r
3.10.0-957.27.2.el7.x86_64
#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 (3.10.0-957.27.2.el7.x86_64) 7 (Core)' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-229.el7.x86_64-advanced-86b03ad5-9029-4a1f-8458-a0efc76024d7' {
menuentry 'CentOS Linux (3.10.0-957.27.2.el7.x86_64) 7 (Core) with debugging' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-229.el7.x86_64-advanced-86b03ad5-9029-4a1f-8458-a0efc76024d7' {
menuentry 'CentOS Linux 7 (Core), with Linux 3.10.0-229.el7.x86_64' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-229.el7.x86_64-advanced-86b03ad5-9029-4a1f-8458-a0efc76024d7' {
menuentry 'CentOS Linux 7 (Core), with Linux 0-rescue-cb7c664a665849e4bcf0a3cbc5de727c' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-cb7c664a665849e4bcf0a3cbc5de727c-advanced-86b03ad5-9029-4a1f-8458-a0efc76024d7' {

查看和修改开机自启动的内核

#grub2-editenv list
saved_entry=CentOS Linux (3.10.0-957.27.2.el7.x86_64) 7 (Core)
#grub2-set-default 'CentOS Linux (3.10.0-957.27.2.el7.x86_64) 7 (Core)'