在 RHEL/CentOS 系统上使用 YUM history 命令回滚升级操作 ====== 为服务器打补丁是 Linux 系统管理员的一项重要任务，为的是让系统更加稳定，性能更加优化。厂商经常会发布一些安全/高危的补丁包，相关软件需要升级以防范潜在的安全风险。 Yum （Yellowdog Update Modified） 是 CentOS 和 RedHat 系统上用的 RPM 包管理工具，`yum history` 命令允许系统管理员将系统回滚到上一个状态，但由于某些限制，回滚不是在所有情况下都能成功，有时 `yum` 命令可能什么都不做，有时可能会删掉一些其他的包。 我建议你在升级之前还是要做一个完整的系统备份，而 `yum history` 并不能用来替代系统备份的。系统备份能让你将系统还原到任意时候的节点状态。 **推荐阅读：** - [在 RHEL/CentOS 系统上使用 YUM 命令管理软件包][1] - [在 Fedora 系统上使用 DNF （YUM 的一个分支）命令管理软件包 ][2] - [如何让 history 命令显示日期和时间][3] 某些情况下，安装的应用程序在升级了补丁之后不能正常工作或者出现一些错误（可能是由于库不兼容或者软件包升级导致的），那该怎么办呢？ 与应用开发团队沟通，并找出导致库和软件包的问题所在，然后使用 `yum history` 命令进行回滚。 **注意：** * 它不支持回滚 selinux，selinux-policy-*，kernel，glibc （以及依赖 glibc 的包，比如 gcc）。 * 不建议将系统降级到更低的版本（比如 CentOS 6.9 降到 CentOS 6.8），这会导致系统处于不稳定的状态 让我们先来看看系统上有哪些包可以升级，然后挑选出一些包来做实验。 ``` # yum update Loaded plugins: fastestmirror, security Setting up Update Process Loading mirror speeds from cached hostfile epel/metalink | 12 kB 00:00 * epel: mirror.csclub.uwaterloo.ca base | 3.7 kB 00:00 dockerrepo | 2.9 kB 00:00 draios | 2.9 kB 00:00 draios/primary_db | 13 kB 00:00 epel | 4.3 kB 00:00 epel/primary_db | 5.9 MB 00:00 extras | 3.4 kB 00:00 updates | 3.4 kB 00:00 updates/primary_db | 2.5 MB 00:00 Resolving Dependencies --> Running transaction check ---> Package git.x86_64 0:1.7.1-8.el6 will be updated ---> Package git.x86_64 0:1.7.1-9.el6_9 will be an update ---> Package httpd.x86_64 0:2.2.15-60.el6.centos.4 will be updated ---> Package httpd.x86_64 0:2.2.15-60.el6.centos.5 will be an update ---> Package httpd-tools.x86_64 0:2.2.15-60.el6.centos.4 will be updated ---> Package httpd-tools.x86_64 0:2.2.15-60.el6.centos.5 will be an update ---> Package perl-Git.noarch 0:1.7.1-8.el6 will be updated ---> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be an update --> Finished Dependency Resolution Dependencies Resolved ================================================================================================= Package Arch Version Repository Size ================================================================================================= Updating: git x86_64 1.7.1-9.el6_9 updates 4.6 M httpd x86_64 2.2.15-60.el6.centos.5 updates 836 k httpd-tools x86_64 2.2.15-60.el6.centos.5 updates 80 k perl-Git noarch 1.7.1-9.el6_9 updates 29 k Transaction Summary ================================================================================================= Upgrade 4 Package(s) Total download size: 5.5 M Is this ok [y/N]: n ``` 你会发现 `git` 包可以被升级，那我们就用它来实验吧。运行下面命令获得软件包的版本信息（当前安装的版本和可以升级的版本）。 ``` # yum list git Loaded plugins: fastestmirror, security Setting up Update Process Loading mirror speeds from cached hostfile * epel: mirror.csclub.uwaterloo.ca Installed Packages git.x86_64 1.7.1-8.el6 @base Available Packages git.x86_64 1.7.1-9.el6_9 updates ``` 运行下面命令来将 `git` 从 `1.7.1-8` 升级到 `1.7.1-9`。 ``` # yum update git Loaded plugins: fastestmirror, presto Setting up Update Process Loading mirror speeds from cached hostfile * base: repos.lax.quadranet.com * epel: fedora.mirrors.pair.com * extras: mirrors.seas.harvard.edu * updates: mirror.sesp.northwestern.edu Resolving Dependencies --> Running transaction check ---> Package git.x86_64 0:1.7.1-8.el6 will be updated --> Processing Dependency: git = 1.7.1-8.el6 for package: perl-Git-1.7.1-8.el6.noarch ---> Package git.x86_64 0:1.7.1-9.el6_9 will be an update --> Running transaction check ---> Package perl-Git.noarch 0:1.7.1-8.el6 will be updated ---> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be an update --> Finished Dependency Resolution Dependencies Resolved ================================================================================================= Package Arch Version Repository Size ================================================================================================= Updating: git x86_64 1.7.1-9.el6_9 updates 4.6 M Updating for dependencies: perl-Git noarch 1.7.1-9.el6_9 updates 29 k Transaction Summary ================================================================================================= Upgrade 2 Package(s) Total download size: 4.6 M Is this ok [y/N]: y Downloading Packages: Setting up and reading Presto delta metadata Processing delta metadata Package(s) data still to download: 4.6 M (1/2): git-1.7.1-9.el6_9.x86_64.rpm | 4.6 MB 00:00 (2/2): perl-Git-1.7.1-9.el6_9.noarch.rpm | 29 kB 00:00 ------------------------------------------------------------------------------------------------- Total 5.8 MB/s | 4.6 MB 00:00 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Updating : perl-Git-1.7.1-9.el6_9.noarch 1/4 Updating : git-1.7.1-9.el6_9.x86_64 2/4 Cleanup : perl-Git-1.7.1-8.el6.noarch 3/4 Cleanup : git-1.7.1-8.el6.x86_64 4/4 Verifying : git-1.7.1-9.el6_9.x86_64 1/4 Verifying : perl-Git-1.7.1-9.el6_9.noarch 2/4 Verifying : git-1.7.1-8.el6.x86_64 3/4 Verifying : perl-Git-1.7.1-8.el6.noarch 4/4 Updated: git.x86_64 0:1.7.1-9.el6_9 Dependency Updated: perl-Git.noarch 0:1.7.1-9.el6_9 Complete! ``` 验证升级后的 `git` 版本. ``` # yum list git Installed Packages git.x86_64 1.7.1-9.el6_9 @updates 或 # rpm -q git git-1.7.1-9.el6_9.x86_64 ``` 现在我们成功升级这个软件包，可以对它进行回滚了。步骤如下。 ### 使用 YUM history 命令回滚升级操作 首先，使用下面命令获取 yum 操作的 id。下面的输出很清晰地列出了所有需要的信息，例如操作 id、谁做的这个操作（用户名）、操作日期和时间、操作的动作（安装还是升级）、操作影响的包数量。 ``` # yum history 或 # yum history list all Loaded plugins: fastestmirror, presto ID | Login user | Date and time | Action(s) | Altered ------------------------------------------------------------------------------- 13 | root | 2017-08-18 13:30 | Update | 2 12 | root | 2017-08-10 07:46 | Install | 1 11 | root | 2017-07-28 17:10 | E, I, U | 28 EE 10 | root | 2017-04-21 09:16 | E, I, U | 162 EE 9 | root | 2017-02-09 17:09 | E, I, U | 20 EE 8 | root | 2017-02-02 10:45 | Install | 1 7 | root | 2016-12-15 06:48 | Update | 1 6 | root | 2016-12-15 06:43 | Install | 1 5 | root | 2016-12-02 10:28 | E, I, U | 23 EE 4 | root | 2016-10-28 05:37 | E, I, U | 13 EE 3 | root | 2016-10-18 12:53 | Install | 1 2 | root | 2016-09-30 10:28 | E, I, U | 31 EE 1 | root | 2016-07-26 11:40 | E, I, U | 160 EE ``` 上面命令显示有两个包受到了影响，因为 `git` 还升级了它的依赖包 `perl-Git`。 运行下面命令来查看关于操作的详细信息。 ``` # yum history info 13 Loaded plugins: fastestmirror, presto Transaction ID : 13 Begin time : Fri Aug 18 13:30:52 2017 Begin rpmdb : 420:f5c5f9184f44cf317de64d3a35199e894ad71188 End time : 13:30:54 2017 (2 seconds) End rpmdb : 420:d04a95c25d4526ef87598f0dcaec66d3f99b98d4 User : root Return-Code : Success Command Line : update git Transaction performed with: Installed rpm-4.8.0-55.el6.x86_64 @base Installed yum-3.2.29-81.el6.centos.noarch @base Installed yum-plugin-fastestmirror-1.1.30-40.el6.noarch @base Installed yum-presto-0.6.2-1.el6.noarch @anaconda-CentOS-201207061011.x86_64/6.3 Packages Altered: Updated git-1.7.1-8.el6.x86_64 @base Update 1.7.1-9.el6_9.x86_64 @updates Updated perl-Git-1.7.1-8.el6.noarch @base Update 1.7.1-9.el6_9.noarch @updates history info ``` 运行下面命令来回滚 `git` 包到上一个版本。 ``` # yum history undo 13 Loaded plugins: fastestmirror, presto Undoing transaction 53, from Fri Aug 18 13:30:52 2017 Updated git-1.7.1-8.el6.x86_64 @base Update 1.7.1-9.el6_9.x86_64 @updates Updated perl-Git-1.7.1-8.el6.noarch @base Update 1.7.1-9.el6_9.noarch @updates Loading mirror speeds from cached hostfile * base: repos.lax.quadranet.com * epel: fedora.mirrors.pair.com * extras: repo1.dal.innoscale.net * updates: mirror.vtti.vt.edu Resolving Dependencies --> Running transaction check ---> Package git.x86_64 0:1.7.1-8.el6 will be a downgrade ---> Package git.x86_64 0:1.7.1-9.el6_9 will be erased ---> Package perl-Git.noarch 0:1.7.1-8.el6 will be a downgrade ---> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be erased --> Finished Dependency Resolution Dependencies Resolved ================================================================================================= Package Arch Version Repository Size ================================================================================================= Downgrading: git x86_64 1.7.1-8.el6 base 4.6 M perl-Git noarch 1.7.1-8.el6 base 29 k Transaction Summary ================================================================================================= Downgrade 2 Package(s) Total download size: 4.6 M Is this ok [y/N]: y Downloading Packages: Setting up and reading Presto delta metadata Processing delta metadata Package(s) data still to download: 4.6 M (1/2): git-1.7.1-8.el6.x86_64.rpm | 4.6 MB 00:00 (2/2): perl-Git-1.7.1-8.el6.noarch.rpm | 29 kB 00:00 ------------------------------------------------------------------------------------------------- Total 3.4 MB/s | 4.6 MB 00:01 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : perl-Git-1.7.1-8.el6.noarch 1/4 Installing : git-1.7.1-8.el6.x86_64 2/4 Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4 Cleanup : git-1.7.1-9.el6_9.x86_64 4/4 Verifying : git-1.7.1-8.el6.x86_64 1/4 Verifying : perl-Git-1.7.1-8.el6.noarch 2/4 Verifying : git-1.7.1-9.el6_9.x86_64 3/4 Verifying : perl-Git-1.7.1-9.el6_9.noarch 4/4 Removed: git.x86_64 0:1.7.1-9.el6_9 perl-Git.noarch 0:1.7.1-9.el6_9 Installed: git.x86_64 0:1.7.1-8.el6 perl-Git.noarch 0:1.7.1-8.el6 Complete! ``` 回滚后，使用下面命令来检查降级包的版本。 ``` # yum list git 或 # rpm -q git git-1.7.1-8.el6.x86_64 ``` ### 使用YUM downgrade 命令回滚升级 此外，我们也可以使用 YUM `downgrade` 命令回滚升级。 ``` # yum downgrade git-1.7.1-8.el6 perl-Git-1.7.1-8.el6 Loaded plugins: search-disabled-repos, security, ulninfo Setting up Downgrade Process Resolving Dependencies --> Running transaction check ---> Package git.x86_64 0:1.7.1-8.el6 will be a downgrade ---> Package git.x86_64 0:1.7.1-9.el6_9 will be erased ---> Package perl-Git.noarch 0:1.7.1-8.el6 will be a downgrade ---> Package perl-Git.noarch 0:1.7.1-9.el6_9 will be erased --> Finished Dependency Resolution Dependencies Resolved ================================================================================================= Package Arch Version Repository Size ================================================================================================= Downgrading: git x86_64 1.7.1-8.el6 base 4.6 M perl-Git noarch 1.7.1-8.el6 base 29 k Transaction Summary ================================================================================================= Downgrade 2 Package(s) Total download size: 4.6 M Is this ok [y/N]: y Downloading Packages: (1/2): git-1.7.1-8.el6.x86_64.rpm | 4.6 MB 00:00 (2/2): perl-Git-1.7.1-8.el6.noarch.rpm | 28 kB 00:00 ------------------------------------------------------------------------------------------------- Total 3.7 MB/s | 4.6 MB 00:01 Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction Installing : perl-Git-1.7.1-8.el6.noarch 1/4 Installing : git-1.7.1-8.el6.x86_64 2/4 Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4 Cleanup : git-1.7.1-9.el6_9.x86_64 4/4 Verifying : git-1.7.1-8.el6.x86_64 1/4 Verifying : perl-Git-1.7.1-8.el6.noarch 2/4 Verifying : git-1.7.1-9.el6_9.x86_64 3/4 Verifying : perl-Git-1.7.1-9.el6_9.noarch 4/4 Removed: git.x86_64 0:1.7.1-9.el6_9 perl-Git.noarch 0:1.7.1-9.el6_9 Installed: git.x86_64 0:1.7.1-8.el6 perl-Git.noarch 0:1.7.1-8.el6 Complete! ``` 注意： 你也需要降级依赖包，否则它会删掉当前版本的依赖包而不是对依赖包做降级，因为 `downgrade` 命令无法处理依赖关系。 ### 至于 Fedora 用户 命令是一样的，只需要将包管理器名称从 `yum` 改成 `dnf` 就行了。 ``` # dnf list git # dnf history # dnf history info # dnf history undo # dnf list git # dnf downgrade git-1.7.1-8.el6 perl-Git-1.7.1-8.el6 ``` -------------------------------------------------------------------------------- via: https://www.2daygeek.com/rollback-fallback-updates-downgrade-packages-centos-rhel-fedora/ 作者：[2daygeek][a] 译者：[lujun9972](https://github.com/lujun9972) 校对：[wxy](https://github.com/wxy) 本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 [a]:https://www.2daygeek.com/author/2daygeek/ [1]:https://www.2daygeek.com/yum-command-examples-manage-packages-rhel-centos-systems/ [2]:https://www.2daygeek.com/dnf-command-examples-manage-packages-fedora-system/ [3]:https://www.2daygeek.com/display-date-time-linux-bash-history-command/