CentOS7 升级 Linux 内核

一、查看当前版本

uname -r

 二、更新仓库

yum -y update

 三、启用 ELRepo 仓库

rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org
rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm

 四、查看系统内部的包

yum --disablerepo="*" --enablerepo="elrepo-kernel" list available

可以发现，有5.4版本和6.3版本，可供选择：

[root@localhost ~]# yum --disablerepo="*" --enablerepo="elrepo-kernel" list available
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * elrepo-kernel: hkg.mirror.rackspace.com
elrepo-kernel                                                                                                    | 3.0 kB  00:00:00
elrepo-kernel/primary_db                                                                                         | 2.1 MB  00:00:00
Available Packages
elrepo-release.noarch                                               7.0-6.el7.elrepo                                       elrepo-kernel
kernel-lt.x86_64                                                    5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-devel.x86_64                                              5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-doc.noarch                                                5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-headers.x86_64                                            5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-tools.x86_64                                              5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-tools-libs.x86_64                                         5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-lt-tools-libs-devel.x86_64                                   5.4.242-1.el7.elrepo                                   elrepo-kernel
kernel-ml.x86_64                                                    6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-devel.x86_64                                              6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-doc.noarch                                                6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-headers.x86_64                                            6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-tools.x86_64                                              6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-tools-libs.x86_64                                         6.3.1-1.el7.elrepo                                     elrepo-kernel
kernel-ml-tools-libs-devel.x86_64                                   6.3.1-1.el7.elrepo                                     elrepo-kernel
perf.x86_64                                                         5.4.242-1.el7.elrepo                                   elrepo-kernel
python-perf.x86_64  

 五、我们选择安装 5.4 内核

yum --enablerepo=elrepo-kernel install kernel-lt

六、设置 grub2

sudo awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg

[root@localhost ~]# sudo awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg
0 : CentOS Linux (6.3.1-1.el7.elrepo.x86_64) 7 (Core)
1 : CentOS Linux (3.10.0-1160.90.1.el7.x86_64) 7 (Core)
2 : CentOS Linux (3.10.0-327.el7.x86_64) 7 (Core)
3 : CentOS Linux (0-rescue-8de58ed1c51640c69d645d424c2c9945) 7 (Core)
[root@localhost ~]#

选择我们的内核ID，这里为0

sudo grub2-set-default 0

七、更新配置文件并重启到新内核

sudo grub2-mkconfig -o /boot/grub2/grub.cfg
sudo reboot