先查看當前內核版本

~]#uname -a
Linux localhost.localdomain 3.10.0-1160.el7.x86_64 #1 SMP Mon Oct 19 1659 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

查看系統grub內核啟動列表

~]# awk -F' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
0 : CentOS Linux (3.10.0-1160.el7.x86_64) 7 (Core)
1 : CentOS Linux (0-rescue-9c44fe6cef3746b2b96d834164eb6b07) 7 (Core)

安裝epel源

~]#rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
~]#yum install -y https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpm

查看可安裝的內核版本列表

~]# yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
已加載插件：fastestmirror
Loading mirror speeds from cached hostfile

 * elrepo-kernel: ftp.yz.yamagata-u.ac.jp
   elrepo-kernel                                                                      | 3.0 kB  0000
   elrepo-kernel/primary_db                                                           | 2.1 MB  0002
   可安裝的軟件包
   kernel-lt.x86_64                                      5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-devel.x86_64                                5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-doc.noarch                                  5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-headers.x86_64                              5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-tools.x86_64                                5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-tools-libs.x86_64                           5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-lt-tools-libs-devel.x86_64                     5.4.270-1.el7.elrepo             elrepo-kernel
   kernel-ml.x86_64                                      6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-devel.x86_64                                6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-doc.noarch                                  6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-headers.x86_64                              6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-tools.x86_64                                6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-tools-libs.x86_64                           6.7.8-1.el7.elrepo               elrepo-kernel
   kernel-ml-tools-libs-devel.x86_64                     6.7.8-1.el7.elrepo               elrepo-kernel
   perf.x86_64                                           5.4.270-1.el7.elrepo             elrepo-kernel
   python-perf.x86_64                                    5.4.270-1.el7.elrepo             elrepo-kernel

安裝最新的lt穩定版內核

 ~]#yum --disablerepo='*' --enablerepo=elrepo-kernel install kernel-lt -y

查看系統grub內核啟動列表，5.4版本使我們最新安裝的

~]# awk -F' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
0 : CentOS Linux (5.4.270-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (3.10.0-1160.el7.x86_64) 7 (Core)
2 : CentOS Linux (0-rescue-9c44fe6cef3746b2b96d834164eb6b07) 7 (Core)

指定以新安裝的編號0的內核版本為默認啟動內核

~]# grub2-set-default 0

卸載舊內核版本

~]# yum remove kernel -y
已加載插件：fastestmirror
跳過正在運行的內核：kernel-3.10.0-1160.el7.x86_64s
不刪除任何軟件包

重啟機器，以新內核版本加載啟動

~]#reboot

重啟完成后再次查看內核版本，已經升級為最新的5.4版本

~]# uname -a
Linux localhost.localdomain 5.4.270-1.el7.elrepo.x86_64 #1 SMP Fri Mar 1 1736 EST 2024 x86_64 x86_64 x86_64 GNU/Linux