如何将CentOS7升级至CentOS8(详细步骤)
这篇文章以具体的示例来介绍一下从centos 7升级值centos 8的方法。
事前准备
最小化安装centos 7,具体版本如下所示:7.6.1810
[root@liumiao ~]# uname -a linux devops 3.10.0-957.el7.x86_64 #1 smp thu nov 8 23:39:32 utc 2018 x86_64 x86_64 x86_64 gnu/linux [root@liumiao ~]# cat /etc/redhat-release centos linux release 7.6.1810 (core) [root@liumiao ~]#
步骤1: 安装epel-relase、yum-utils和rpmconf
执行命令:yum install yum-utils epel-release -y
执行日志如下所示:
...省略 ======================================================================================================================================== package arch version repository size ======================================================================================================================================== installing: epel-release noarch 7-11 extras 15 k yum-utils noarch 1.1.31-52.el7 base 121 k installing for dependencies: libxml2-python x86_64 2.9.1-6.el7_2.3 base 247 k python-chardet noarch 2.2.1-3.el7 base 227 k python-kitchen noarch 1.1.1-5.el7 base 267 k transaction summary ======================================================================================================================================== install 2 packages (+3 dependent packages) ...省略
安装命令:yum install rpmconf -y
安装日志如下所示:
[root@liumiao ~]# yum install rpmconf -y ...省略 ======================================================================================================================================== package arch version repository size ======================================================================================================================================== installing: rpmconf noarch 0.3.4-1.el7 epel 21 k transaction summary ======================================================================================================================================== install 1 package ...省略 complete!
[root@liumiao ~]#
步骤2: 安装前检查
检查配置:rpmconf -a
执行日志如下所示,如有选择直接使用缺省设定。
[root@liumiao ~]# rpmconf -a [root@liumiao ~]#
检查叶节点:列出和其他rpm没有依赖的软件包
[root@liumiao ~]# package-cleanup --leaves loaded plugins: fastestmirror libsysfs-2.1.0-16.el7.x86_64 [root@liumiao ~]#
检查不再提供的软件包:列出当前仓库中不提供升级的软件包信息
[root@liumiao ~]# package-cleanup --orphans loaded plugins: fastestmirror loading mirror speeds from cached hostfile * base: mirror.bit.edu.cn * epel: hkg.mirror.rackspace.com * extras: mirror.bit.edu.cn * updates: ap.stykers.moe geoip-1.5.0-13.el7.x86_64 ...省略 yum-plugin-fastestmirror-1.1.31-50.el7.noarch [root@liumiao ~]#
步骤3: 安装dnf 并执行dnf update
centos 8使用dnf作为缺省的包管理工具,使用yum安装自己的替代工具dnf并删除自己。
安装命令:yum install dnf -y
执行日志如下所示:
[root@liumiao ~]# yum install dnf -y ...省略 ======================================================================================================================================== package arch version repository size ======================================================================================================================================== installing: dnf noarch 4.0.9.2-1.el7_6 extras 357 k installing for dependencies: deltarpm x86_64 3.6-3.el7 base 82 k dnf-data noarch 4.0.9.2-1.el7_6 extras 51 k libcomps x86_64 0.1.8-12.el7 extras 75 k libdnf x86_64 0.22.5-1.el7_6 extras 533 k libmodulemd x86_64 1.6.3-1.el7 extras 141 k librepo x86_64 1.8.1-7.el7 base 81 k libreport-filesystem x86_64 2.1.11-43.el7.centos base 40 k libsolv x86_64 0.6.34-4.el7 base 329 k libyaml x86_64 0.1.4-11.el7_0 base 55 k python-enum34 noarch 1.0.4-1.el7 base 52 k python2-dnf noarch 4.0.9.2-1.el7_6 extras 414 k python2-hawkey x86_64 0.22.5-1.el7_6 extras 68 k python2-libcomps x86_64 0.1.8-12.el7 extras 47 k python2-libdnf x86_64 0.22.5-1.el7_6 extras 608 k transaction summary ======================================================================================================================================== install 1 package (+14 dependent packages) ...省略 [root@liumiao ~]#
清除yum:dnf -y remove yum yum-metadata-parser && rm -rf /etc/yum
执行日志如下所示:
[root@liumiao ~]# dnf -y remove yum yum-metadata-parser dependencies resolved. ======================================================================================================================================== package arch version repository size ======================================================================================================================================== removing: yum noarch 3.4.3-161.el7.centos @system 5.6 m yum-metadata-parser x86_64 1.1.4-10.el7 @system 57 k removing dependent packages: yum-plugin-fastestmirror noarch 1.1.31-50.el7 @system 53 k yum-utils noarch 1.1.31-52.el7 @system 337 k transaction summary ======================================================================================================================================== remove 4 packages freed space: 6.0 m running transaction check transaction check succeeded. running transaction test transaction test succeeded. running transaction preparing : 1/1 erasing : yum-utils-1.1.31-52.el7.noarch 1/4 erasing : yum-plugin-fastestmirror-1.1.31-50.el7.noarch 2/4 erasing : yum-3.4.3-161.el7.centos.noarch 3/4 erasing : yum-metadata-parser-1.1.4-10.el7.x86_64 4/4 verifying : yum-3.4.3-161.el7.centos.noarch 1/4 verifying : yum-metadata-parser-1.1.4-10.el7.x86_64 2/4 verifying : yum-plugin-fastestmirror-1.1.31-50.el7.noarch 3/4 verifying : yum-utils-1.1.31-52.el7.noarch 4/4 removed: yum-3.4.3-161.el7.centos.noarch yum-metadata-parser-1.1.4-10.el7.x86_64 yum-plugin-fastestmirror-1.1.31-50.el7.noarch yum-utils-1.1.31-52.el7.noarch complete! [root@liumiao ~]# ls /etc/yum pluginconf.d protected.d vars [root@liumiao ~]# rm -rf /etc/yum [root@liumiao ~]#
就像使用yum update那样使用dnf update进行更新。
[root@liumiao ~]# dnf upgrade extra packages for enterprise linux 7 - x86_64 5.6 mb/s | 16 mb 00:02 centos-7 - base 3.5 mb/s | 10 mb 00:02 centos-7 - updates 2.9 mb/s | 5.4 mb 00:01 centos-7 - extras 40 kb/s | 251 kb 00:06 ...省略 ======================================================================================================================================== package arch version repository size ======================================================================================================================================== upgrading: epel-release noarch 7-12 epel 15 k ...省略 tzdata noarch 2019c-1.el7 updates 493 k installing dependencies: bind-export-libs x86_64 32:9.11.4-9.p2.el7 base 1.1 m geoipupdate x86_64 2.5.0-1.el7 base 35 k kernel x86_64 3.10.0-1062.4.3.el7 updates 50 m transaction summary ======================================================================================================================================== install 3 packages upgrade 164 packages total download size: 259 m is this ok [y/n]: y downloading packages: ...省略 installed: bind-export-libs-32:9.11.4-9.p2.el7.x86_64 geoipupdate-2.5.0-1.el7.x86_64 kernel-3.10.0-1062.4.3.el7.x86_64 complete! [root@liumiao ~]#
使用dnf更新centos 8的包
执行日志如下所示:
[root@liumiao ~]# dnf -y upgrade http://mirror.bytemark.co.uk/centos/8/baseos/x86_64/os/packages/centos-release-8.0-0.1905.0.9.el8.x86_64.rpm extra packages for enterprise linux 7 - x86_64 4.3 mb/s | 16 mb 00:03 last metadata expiration check: 0:00:01 ago on wed 20 nov 2019 07:58:07 am est. centos-release-8.0-0.1905.0.9.el8.x86_64.rpm 13 kb/s | 26 kb 00:01 dependencies resolved. ======================================================================================================================================== package arch version repository size ======================================================================================================================================== upgrading: centos-release x86_64 8.0-0.1905.0.9.el8 @commandline 26 k transaction summary ======================================================================================================================================== upgrade 1 package total size: 26 k downloading packages: running transaction check transaction check succeeded. running transaction test transaction test succeeded. running transaction preparing : 1/1 upgrading : centos-release-8.0-0.1905.0.9.el8.x86_64 1/2 cleanup : centos-release-7-7.1908.0.el7.centos.x86_64 2/2 verifying : centos-release-8.0-0.1905.0.9.el8.x86_64 1/2 verifying : centos-release-7-7.1908.0.el7.centos.x86_64 2/2 upgraded: centos-release-8.0-0.1905.0.9.el8.x86_64 complete! [root@liumiao ~]#
更新epel仓库
执行日志如下所示:
[root@liumiao ~]# dnf -y upgrade https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm extra packages for enterprise linux 7 - x86_64 578 kb/s | 16 mb 00:28 centos-8 - base 635 kb/s | 7.9 mb 00:12 centos-8 - extras 1.7 kb/s | 2.1 kb 00:01 centos-8 - appstream 1.3 mb/s | 6.3 mb 00:04 epel-release-latest-8.noarch.rpm 7.7 kb/s | 21 kb 00:02 dependencies resolved. ======================================================================================================================================== package arch version repository size ======================================================================================================================================== upgrading: epel-release noarch 8-7.el8 @commandline 21 k transaction summary ======================================================================================================================================== upgrade 1 package total size: 21 k downloading packages: running transaction check transaction check succeeded. running transaction test transaction test succeeded. running transaction preparing : 1/1 upgrading : epel-release-8-7.el8.noarch 1/2 cleanup : epel-release-7-12.noarch 2/2 verifying : epel-release-8-7.el8.noarch 1/2 verifying : epel-release-7-12.noarch 2/2 upgraded: epel-release-8-7.el8.noarch complete! [root@liumiao ~]#
此时确认版本信息,已经发生了变化
[root@liumiao ~]# cat /etc/redhat-release centos linux release 8.0.1905 (core) [root@liumiao ~]#
步骤4: 删除无用文件和centos 7的内核并安装centos 8的内核
删除无用的临时文件:dnf clean all
执行日志如下所示:
[root@liumiao ~]# dnf clean all 62 files removed [root@liumiao ~]#
删除centos 7的旧核: rpm -e `rpm -q kernel`
执行日志如下所示:
[root@liumiao ~]# rpm -e `rpm -q kernel` [root@liumiao ~]#
确认删除冲突的包
[root@liumiao ~]# rpm -e --nodeps sysvinit-tools [root@liumiao ~]#
更新centos 8系统
[root@liumiao ~]# dnf -y --releasever=8 --allowerasing --setopt=deltarpm=false distro-sync extra packages for enterprise linux 8 - x86_64 2.0 mb/s | 3.5 mb 00:01 centos-8 - base 160 kb/s | 7.9 mb 00:50 centos-8 - appstream 1.6 mb/s | 6.3 mb 00:03 centos-8 - extras 950 b/s | 2.1 kb 00:02 last metadata expiration check: 0:00:02 ago on wed 20 nov 2019 08:09:51 am est. dependencies resolved. ======================================================================================================================================== package arch version repository size ======================================================================================================================================== upgrading: rpmconf noarch 1.0.20-1.el8 epel 26 k ...省略 removed: deltarpm-3.6-3.el7.x86_64 libselinux-python-2.5-14.1.el7.x86_64 libxml2-python-2.9.1-6.el7_2.3.x86_64 newt-python-0.52.15-4.el7.x86_64 python-2.7.5-86.el7.x86_64 python-chardet-2.2.1-3.el7.noarch python-firewall-0.6.3-2.el7_7.2.noarch python-kitchen-1.1.1-5.el7.noarch python-libs-2.7.5-86.el7.x86_64 python-linux-procfs-0.4.11-4.el7.noarch python-schedutils-0.4-6.el7.x86_64 python-slip-0.4.0-4.el7.noarch python-slip-dbus-0.4.0-4.el7.noarch python-urlgrabber-3.10-9.el7.noarch python2-dnf-4.0.9.2-1.el7_6.noarch python2-hawkey-0.22.5-1.el7_6.x86_64 python2-libcomps-0.1.8-12.el7.x86_64 python2-libdnf-0.22.5-1.el7_6.x86_64 pyxattr-0.5.1-5.el7.x86_64 rpm-python-4.11.3-40.el7.x86_64 systemd-sysv-219-67.el7_7.2.x86_64 complete! [root@liumiao ~]#
此时通过uname -a确认内核状态,仍是3.10.
[root@liumiao ~]# uname -a linux devops 3.10.0-957.el7.x86_64 #1 smp thu nov 8 23:39:32 utc 2018 x86_64 x86_64 x86_64 gnu/linux [root@liumiao ~]# cat /etc/redhat-release centos linux release 8.0.1905 (core) [root@liumiao ~]#
由于前文已经更新,此时如执行dnf -y install kernel-core会提示already updated,接下来更新一下centos 8的最小化安装的相关package,执行如下命令即可:
[root@liumiao ~]# dnf -y groupupdate "core" "minimal install" last metadata expiration check: 0:13:34 ago on wed 20 nov 2019 08:09:51 am est. dependencies resolved. ======================================================================================================================================== package arch version repository size ======================================================================================================================================== installing group/module packages: dnf-plugin-spacewalk noarch 2.8.5-11.module_el8.0.0+180+337688dc appstream 24 k dnf-plugins-core noarch 4.0.2.2-3.el8 baseos 59 k ...省略 [root@liumiao ~]#
步骤5: 重启系统
重启之后即可确认内核和版本文件信息均已升至最新
[root@liumiao ~]# uname -a linux devops 4.18.0-80.11.2.el8_0.x86_64 #1 smp tue sep 24 11:32:19 utc 2019 x86_64 x86_64 x86_64 gnu/linux [root@liumiao ~]# cat /etc/redhat-release centos linux release 8.0.1905 (core) [root@liumiao ~]#
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持。