一、检查本地系统环境

1.检查系统版本

[root@jeven ~]# cat /etc/os-release NAME="Centos Linux"VERSioN="7 (Core)"ID="centos"ID_LIKE="rhel fedora"VERSION_ID="7"PRETTY_NAME="CentOS Linux 7 (Core)"ANSI_COLOR="0;31"CPE_NAME="cpe:/o:centos:centos:7"HOME_URL="https://www.centos.org/"BUG_REPORT_URL="Https://bugs.centos.org/"CENTOS_MANTISBT_PROJECT="CentOS-7"CENTOS_MANTISBT_PROJECT_VERSION="7"REDHAT_SUPPORT_PRODUCT="centos"REDHAT_SUPPORT_PRODUCT_VERSION="7"

2.检查系统内核版本

[root@jeven ~]# uname -r 3.10.0-957.el7.x86_64

二、小版本升级内核

1.列出yum仓库的内核包版本

确保yum仓库的正常，本次实践用的是阿里的镜像源。

[root@jeven yum.repos.d]# yum list kernelLoaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile * epel: mirrors.bfsu.edu.cnInstalled Packageskernel.x86_64      3.10.0-957.el7            @anacondaAvailable Packageskernel.x86_64      3.10.0-1160.81.1.el7      updates

2.升级内核

直接更新内核版本，此方法适用于更新内核补丁。

[root@jeven yum.repos.d]# yum update -y kernelLoaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfileepel/x86_64/metalink           | 8.5 kB  00:00:00      * epel: mirrors.bfsu.edu.cnbase                           | 3.6 kB  00:00:00     docker-ce-stable               | 3.5 kB  00:00:00     epel                           | 4.7 kB  00:00:00     extras                         | 2.9 kB  00:00:00     updates                        | 2.9 kB  00:00:00     (1/3): epel/x86_64/updateinfo  | 1.0 MB  00:00:00     (2/3): epel/x86_64/primary_db  | 7.0 MB  00:00:01     (3/3): updates/7/x86_64/primary_db                         |  19 MB  00:00:09     Resolving Dependencies--> Running transaction check---> Package kernel.x86_64 0:3.10.0-1160.83.1.el7 will be installed--> Processing Dependency: linux-firmware >= 20190429-72 for package: kernel-3.10.0-1160.83.1.el7.x86_64--> Running transaction check---> Package linux-firmware.noarch 0:20180911-69.git85c5d90.el7 will be updated---> Package linux-firmware.noarch 0:20200421-80.git78c0348.el7_9 will be an update--> Finished Dependency ResolutionDependencies Resolved====================================================================================================================================================================== Package     ArchVersion                   Repository                        Size======================================================================================================================================================================Installing: kernel      x86_64                          3.10.0-1160.83.1.el7      updates                           52 MUpdating for dependencies: linux-firmware                          noarch                          20200421-80.git78c0348.el7_9                          updates                           80 MTransaction Summary======================================================================================================================================================================Install  1 PackageUpgrade             ( 1 Dependent package)Total download size: 132 MDownloading packages:No Presto metadata available for updates(1/2): kernel-3.10.0-1160.83.1.el7.x86_64.rpm              |  52 MB  00:00:31     (2/2): linux-firmware-20200421-80.git78c0348.el7_9.noarch.rpm                          |  80 MB  00:00:48     ----------------------------------------------------------------------------------------------------------------------------------------------------------------------Total                 2.7 MB/s | 132 MB  00:00:48     Running transaction checkRunning transaction testTransaction test succeededRunning transaction  Updating   : linux-firmware-20200421-80.git78c0348.el7_9.noarch             1/3   Installing : kernel-3.10.0-1160.83.1.el7.x86_64 2/3   Cleanup    : linux-firmware-20180911-69.git85c5d90.el7.noarch               3/3   Verifying  : kernel-3.10.0-1160.83.1.el7.x86_64 1/3   Verifying  : linux-firmware-20200421-80.git78c0348.el7_9.noarch             2/3   Verifying  : linux-firmware-20180911-69.git85c5d90.el7.noarch               3/3 Installed:  kernel.x86_64 0:3.10.0-1160.83.1.el7                Dependency Updated:  linux-firmware.noarch 0:20200421-80.git78c0348.el7_9Complete!

3.重启并检查内核版本

• 重启服务器

reboot

• 检查内核版本

重启完成，发现内核版本已经升级为【3.10.0-1160.83.1.el7.x86_64】

[root@jeven ~]# uname -r 3.10.0-1160.83.1.el7.x86_64

三、大版本升级内核

1.导入公钥

ELRepo是一个为Linux提供驱动程序和内核映像的存储库，这里的内核大版本升级方案就是采用ELRepo提供的内核通道。

[root@jeven ~]# rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org[root@jeven ~]#

2.下载并安装elrepo仓库

ELRepo内核下载地址：https://elrepo.org/linux/kernel/el7/x86_64/RPMS/，如果服务器不能联网，可离线下载。

[root@jeven ~]# yum install https://www.elrepo.org/elrepo-release-7.el7.elrepo.noarch.rpmLoaded plugins: fastestmirror, langpackselrepo-release-7.el7.elrepo.noarch.rpm                     | 8.7 kB  00:00:00     Examining /var/tmp/yum-root-RRC6Uo/elrepo-release-7.el7.elrepo.noarch.rpm: elrepo-release-7.0-6.el7.elrepo.noarchMarking /var/tmp/yum-root-RRC6Uo/elrepo-release-7.el7.elrepo.noarch.rpm to be installedResolving Dependencies--> Running transaction check---> Package elrepo-release.noarch 0:7.0-6.el7.elrepo will be installed--> Finished Dependency ResolutionDependencies Resolved====================================================================================================================================================================== Package Arch                        Version   Repository                    Size======================================================================================================================================================================Installing: elrepo-release                      noarch                      7.0-6.el7.elrepo                      /elrepo-release-7.el7.elrepo.noarch                      5.0 kTransaction Summary======================================================================================================================================================================Install  1 PackageTotal size: 5.0 kInstalled size: 5.0 kIs this ok [y/d/N]: yDownloading packages:Running transaction checkRunning transaction testTransaction test succeededRunning transaction  Installing : elrepo-release-7.0-6.el7.elrepo.noarch                         1/1   Verifying  : elrepo-release-7.0-6.el7.elrepo.noarch                         1/1 Installed:  elrepo-release.noarch 0:7.0-6.el7.elrepo            Complete!

3.载入elrepo-kernel元数据

[root@jeven ~]# yum --disablerepo=\* --enablerepo=elrepo-kernel repolistLoaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile * elrepo-kernel: mirrors.tuna.tsinghua.edu.cnelrepo-kernel                  | 3.0 kB  00:00:00     elrepo-kernel/primary_db       | 2.1 MB  00:00:00     repo id                     repo name           statuselrepo-kernel               ELRepo.org CommUnity Enterprise Linux Kernel Repository - el7               34repolist: 34

4.列出rpm包

列出elrepo-kernel的rpm包

[root@jeven ~]# yum --disablerepo=\* --enablerepo=elrepo-kernel list kernel*Loaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile * elrepo-kernel: mirrors.tuna.tsinghua.edu.cnInstalled Packageskernel.x86_64              3.10.0-957.el7@anaconda    kernel.x86_64              3.10.0-1160.83.1.el7                      @updates     kernel-tools.x86_64        3.10.0-957.el7@anaconda    kernel-tools-libs.x86_64   3.10.0-957.el7@anaconda    Available Packageskernel-lt.x86_64           5.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-devel.x86_64     5.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-doc.noarch       5.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-headers.x86_64   5.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-tools.x86_64     5.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-tools-libs.x86_645.4.230-1.el7.elrepo                      elrepo-kernelkernel-lt-tools-libs-devel.x86_64                      5.4.230-1.el7.elrepo                      elrepo-kernelkernel-ml.x86_64           6.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-devel.x86_64     6.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-doc.noarch       6.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-headers.x86_64   6.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-tools.x86_64     6.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-tools-libs.x86_646.1.8-1.el7.elrepo                        elrepo-kernelkernel-ml-tools-libs-devel.x86_64                      6.1.8-1.el7.elrepo                        elrepo-kerne

5.安装最新版本kernel

[root@jeven ~]# yum --disablerepo=\* --enablerepo=elrepo-kernel install -y kernel-ml.x86_64Loaded plugins: fastestmirror, langpacksLoading mirror speeds from cached hostfile * elrepo-kernel: mirrors.tuna.tsinghua.edu.cnResolving Dependencies--> Running transaction check---> Package kernel-ml.x86_64 0:6.1.8-1.el7.elrepo will be installed--> Finished Dependency ResolutionDependencies Resolved====================================================================================================================================================================== Package  Arch  Version            Repository    Size======================================================================================================================================================================Installing: kernel-mlx86_646.1.8-1.el7.elrepo elrepo-kernel 60 MTransaction Summary======================================================================================================================================================================Install  1 PackageTotal download size: 60 MInstalled size: 284 MDownloading packages:kernel-ml-6.1.8-1.el7.elrepo.x86_64.rpm                    |  60 MB  00:00:02     Running transaction checkRunning transaction testTransaction test succeededRunning transaction  Installing : kernel-ml-6.1.8-1.el7.elrepo.x86_641/1   Verifying  : kernel-ml-6.1.8-1.el7.elrepo.x86_641/1 Installed:  kernel-ml.x86_64 0:6.1.8-1.el7.elrepo               Complete!

6.查看内核是否载入到grub2

查看系统上的所有可用内核

[root@jeven ~]# awk -F\' '$1=="menuentry " {print i++ " : " $2}' /etc/grub2.cfg0 : CentOS Linux (6.1.8-1.el7.elrepo.x86_64) 7 (Core)1 : CentOS Linux (3.10.0-1160.83.1.el7.x86_64) 7 (Core)2 : CentOS Linux (3.10.0-957.el7.x86_64) 7 (Core)3 : CentOS Linux (0-rescue-626024fee7b34ca3acd67183D6f1ca99) 7 (Core)

7.设置新的内核为grub2的默认版本

• 通过 grub2-set-default命令设置默认启动版本

[root@jeven ~]# grub2-set-default 0[root@jeven ~]# 

• 通过编辑 /etc/default/grub 文件设置默认启动版本

[root@jeven ~]# cat /etc/default/grub GRUB_TIMEOUT=5GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"GRUB_DEFAULT=0GRUB_DISABLE_SUBMENU=trueGRUB_TERMINAL_OUTPUT="console"GRUB_CMDLINE_LINUX="crashkernel=auto rd.lvm.lv=centos/root rd.lvm.lv=centos/swap rhgb quiet"GRUB_DISABLE_RECOVERY="true"

• 生成 grub 配置文件并重启

[root@jeven ~]# grub2-mkconfig -o /boot/grub2/grub.cfgGenerating grub configuration file ...Found linux image: /boot/vmlinuz-6.1.8-1.el7.elrepo.x86_64Found initrd image: /boot/initramfs-6.1.8-1.el7.elrepo.x86_64.imgFound linux image: /boot/vmlinuz-3.10.0-1160.83.1.el7.x86_64Found initrd image: /boot/initramfs-3.10.0-1160.83.1.el7.x86_64.imgFound linux image: /boot/vmlinuz-3.10.0-957.el7.x86_64Found initrd image: /boot/initramfs-3.10.0-957.el7.x86_64.imgFound linux image: /boot/vmlinuz-0-rescue-626024fee7b34ca3acd67183d6f1ca99Found initrd image: /boot/initramfs-0-rescue-626024fee7b34ca3acd67183d6f1ca99.imgdone

• 重启

reboot

8.检查重启后的系统内核版本

重启系统后，发现系统内核已经成功升级。

[root@jeven ~]# uname -r 6.1.8-1.el7.elrepo.x86_64

来源地址：https://blog.csdn.net/jks212454/article/details/128833232