网站登不上去的原因,南沙seo培训,网站开发市场前景,视频网站开发公司有哪些公司注#xff1a;英文引文#xff0c;机翻未校。 在 RHEL/CentOS 系统上使用 YUM history 命令回滚升级操作
作者#xff1a; 2daygeek 译者#xff1a; LCTT DarkSun
为服务器打补丁是 Linux 系统管理员的一项重要任务#xff0c;为的是让系统更加稳定#xff0c;性能更加…注英文引文机翻未校。 在 RHEL/CentOS 系统上使用 YUM history 命令回滚升级操作
作者 2daygeek 译者 LCTT DarkSun
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。
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。
回滚 / 降级注意事项
它不支持回滚 selinuxselinux-policy-*kernelglibc 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 SizeUpdating:git x86_64 1.7.1-9.el6_9 updates 4.6 Mhttpd x86_64 2.2.15-60.el6.centos.5 updates 836 khttpd-tools x86_64 2.2.15-60.el6.centos.5 updates 80 kperl-Git noarch 1.7.1-9.el6_9 updates 29 k
Transaction SummaryUpgrade 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 SizeUpdating: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 SummaryUpgrade 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 TransactionUpdating : perl-Git-1.7.1-9.el6_9.noarch 1/4Updating : git-1.7.1-9.el6_9.x86_64 2/4Cleanup : perl-Git-1.7.1-8.el6.noarch 3/4Cleanup : git-1.7.1-8.el6.x86_64 4/4Verifying : git-1.7.1-9.el6_9.x86_64 1/4Verifying : perl-Git-1.7.1-9.el6_9.noarch 2/4Verifying : git-1.7.1-8.el6.x86_64 3/4Verifying : 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。
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 | 212 | root | 2017-08-10 07:46 | Install | 111 | root | 2017-07-28 17:10 | E, I, U | 28 EE10 | root | 2017-04-21 09:16 | E, I, U | 162 EE9 | root | 2017-02-09 17:09 | E, I, U | 20 EE8 | root | 2017-02-02 10:45 | Install | 17 | root | 2016-12-15 06:48 | Update | 16 | root | 2016-12-15 06:43 | Install | 15 | root | 2016-12-02 10:28 | E, I, U | 23 EE4 | root | 2016-10-28 05:37 | E, I, U | 13 EE3 | root | 2016-10-18 12:53 | Install | 12 | root | 2016-09-30 10:28 | E, I, U | 31 EE1 | 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 baseInstalled yum-3.2.29-81.el6.centos.noarch baseInstalled yum-plugin-fastestmirror-1.1.30-40.el6.noarch baseInstalled 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 baseUpdate 1.7.1-9.el6_9.x86_64 updatesUpdated perl-Git-1.7.1-8.el6.noarch baseUpdate 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 2017Updated git-1.7.1-8.el6.x86_64 baseUpdate 1.7.1-9.el6_9.x86_64 updatesUpdated perl-Git-1.7.1-8.el6.noarch baseUpdate 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 SizeDowngrading:git x86_64 1.7.1-8.el6 base 4.6 Mperl-Git noarch 1.7.1-8.el6 base 29 k
Transaction SummaryDowngrade 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 TransactionInstalling : perl-Git-1.7.1-8.el6.noarch 1/4Installing : git-1.7.1-8.el6.x86_64 2/4Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4Cleanup : git-1.7.1-9.el6_9.x86_64 4/4Verifying : git-1.7.1-8.el6.x86_64 1/4Verifying : perl-Git-1.7.1-8.el6.noarch 2/4Verifying : git-1.7.1-9.el6_9.x86_64 3/4Verifying : 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 SizeDowngrading:git x86_64 1.7.1-8.el6 base 4.6 Mperl-Git noarch 1.7.1-8.el6 base 29 k
Transaction SummaryDowngrade 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 TransactionInstalling : perl-Git-1.7.1-8.el6.noarch 1/4Installing : git-1.7.1-8.el6.x86_64 2/4Cleanup : perl-Git-1.7.1-9.el6_9.noarch 3/4Cleanup : git-1.7.1-9.el6_9.x86_64 4/4Verifying : git-1.7.1-8.el6.x86_64 1/4Verifying : perl-Git-1.7.1-8.el6.noarch 2/4Verifying : git-1.7.1-9.el6_9.x86_64 3/4Verifying : 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.el6How to display Date and Time in history command
如何在历史记录命令中显示日期和时间
January 20, 2020
We all are familiar with the history command. It stores all the commands executed by bash in the terminal into the .bash_history file, which helps us recheck the previously executed commands for further investigation.
我们都熟悉 history 命令。它将 bash 在终端执行的所有命令存储到 .bash_history 文件中这将有助于我们重新检查用户之前执行的命令以进行进一步调查。
By default, the history command shows only the commands executed by users and does not print the date and time, although it logs the time when the command was run.
默认情况下history 命令仅显示用户执行的命令不会打印日期和时间但会记录命令运行的时间。
Whenever you run the history command, it looks for an environment variable called HISTTIMEFORMAT, which tells it how to format the date and time with the history command.
每当你运行 history 命令时它会寻找一个名为 HISTTIMEFORMAT 的环境变量该变量用于指定如何在 history 命令中格式化日期和时间。
If the value is null or not set, it will show default results, like most systems do (without date and time).
如果该值为空或未设置则会显示默认结果就像大多数系统一样不显示日期和时间。
HISTTIMEFORMAT takes values from strftime (strftime – convert date and time to a string). When you have date and time in the history command output, it might help you track issues more easily.
HISTTIMEFORMAT 从 strftimestrftime — 将日期和时间转换为字符串中获取值。当 history 命令的输出中包含日期和时间时它可以帮助你更轻松地跟踪问题。 %T: Replaced by the time (%H:%M:%S). %T替换为时间%H:%M:%S。 %F: Equivalent to %Y-%m-%d (the ISO 8601:2000 standard date format). %F相当于 %Y-%m-%dISO 8601:2000 标准日期格式。
See below for the default history command output.
请参阅下面的默认 history 命令输出。
# history1 yum install -y mysql-server mysql-client2 service mysqld start3 sysdig proc.namesshd4 sysdig -c topprocs_net5 sysdig proc.namesshd6 sysdig proc.namesshd | more7 sysdig fd.name/var/log/auth.log | more8 sysdig fd.name/var/log/mysqld.log9 sysdig -cl10 sysdig -i httplog11 sysdig -i proc_exec_time12 sysdig -i topprocs_cpu13 sysdig -c topprocs_cpu14 sysdig -c tracers_2_statsd15 sysdig -c topfiles_bytes16 sysdig -c topprocs_cpu17 sysdig -c topprocs_cpu fd.name contains sshd18 sysdig -c topprocs_cpu proc.name contains sshd19 csysdig20 sysdig -c topprocs_cpu21 rpm --import https://s3.amazonaws.com/download.draios.com/DRAIOS-GPG-KEY.public22 curl -s -o /etc/yum.repos.d/draios.repo http://download.draios.com/stable/rpm/draios.repo23 yum install -y epel-release24 yum update25 yum makecache26 yum -y install kernel-devel-$(uname -r)27 yum -y install sysdig28 sysdig29 yum install httpd mysql30 service httpd startWe can set this environment variable in three ways based on our requirements.
我们可以根据需求以三种方式设置这个环境变量。 Temporarily for the current user 临时对当前用户生效 Permanently for the current user or another user 永久对当前用户或其他用户生效 Permanently for all users 永久对所有用户生效
Note: Don’t forget to add a space before the last single quote, otherwise the output will be messy.
注意不要忘记在最后一个单引号之前添加空格否则输出会很混乱。
Method 1: Temporarily for the Current User
方法 1临时对当前用户生效
Run the following command to set the HISTTIMEFORMAT variable temporarily for the current user. This setting will be lost after a reboot.
执行以下命令将 HISTTIMEFORMAT 变量临时设置为当前用户。重启后该设置将失效。
# export HISTTIMEFORMAT%F %T Method 2: Permanently for the Current User
方法 2永久对当前用户生效
Append the following HISTTIMEFORMAT variable to the .bashrc or .bash_profile file to make it permanent for the current user.
将以下 HISTTIMEFORMAT 变量追加到 .bashrc 或 .bash_profile 文件中使其对当前用户永久生效。
# echo HISTTIMEFORMAT%F %T ~/.bashrcor
# echo HISTTIMEFORMAT%F %T ~/.bash_profileRun the following command to apply the changes made to the file.
运行以下命令以使文件中的更改生效。
# source ~/.bashrcor
# source ~/.bash_profileMethod 3: Permanently for All Users
方法 3永久对所有用户生效
Append the following HISTTIMEFORMAT variable to the /etc/profile file to make it permanent for all users.
将以下 HISTTIMEFORMAT 变量追加到 /etc/profile 文件中使其对所有用户永久生效。
# echo HISTTIMEFORMAT%F %T /etc/profileRun the following command to apply the changes made to the file.
运行以下命令以使文件中的更改生效。
# source /etc/profileSee the sample output below.
请参阅以下示例输出。
# history1 2017-08-16 15:30:15 yum install -y mysql-server mysql-client2 2017-08-16 15:30:15 service mysqld start3 2017-08-16 15:30:15 sysdig proc.namesshd4 2017-08-16 15:30:15 sysdig -c topprocs_net5 2017-08-16 15:30:15 sysdig proc.namesshd6 2017-08-16 15:30:15 sysdig proc.namesshd | more7 2017-08-16 15:30:15 sysdig fd.name/var/log/auth.log | more8 2017-08-16 15:30:15 sysdig fd.name/var/log/mysqld.log9 2017-08-16 15:30:15 sysdig -cl10 2017-08-16 15:30:15 sysdig -i httplog11 2017-08-16 15:30:15 sysdig -i proc_exec_time12 2017-08-16 15:30:15 sysdig -i topprocs_cpu13 2017-08-16 15:30:15 sysdig -c topprocs_cpu14 2017-08-16 15:30:15 sysdig -c tracers_2_statsd15 2017-08-16 15:30:15 sysdig -c topfiles_bytes16 2017-08-16 15:30:15 sysdig -c topprocs_cpu17 2017-08-16 15:30:15 sysdig -c topprocs_cpu fd.name contains sshd18 2017-08-16 15:30:15 sysdig -c topprocs_cpu proc.name contains sshd19 2017-08-16 15:30:15 csysdig20 2017-08-16 15:30:15 sysdig -c topprocs_cpu21 2017-08-16 15:30:15 rpm --import https://s3.amazonaws.com/download.draios.com/DRAIOS-GPG-KEY.public22 2017-08-16 15:30:15 curl -s -o /etc/yum.repos.d/draios.repo http://download.draios.com/stable/rpm/draios.repo23 2017-08-16 15:30:15 yum install -y epel-release24 2017-08-16 15:30:15 yum update25 2017-08-16 15:30:15 yum makecache26 2017-08-16 15:30:15 yum -y install kernel-devel-$(uname -r)27 2017-08-16 15:30:15 yum -y install sysdig28 2017-08-16 15:30:15 sysdig29 2017-08-16 15:30:15 yum install httpd mysql30 2017-08-16 15:30:15 service httpd startvia: How To Use YUM History Command To Rollback An Updates In RHEL/CentOS Systems | 2DayGeek https://www.2daygeek.com/rollback-fallback-updates-downgrade-packages-centos-rhel-fedora/ 作者2daygeek 译者lujun9972 校对wxy 本文由 LCTT 原创编译Linux中国. 荣誉推出 | 2018-01-18 08:47 How To Display Date And Time In History Command https://www.2daygeek.com/display-date-time-linux-bash-history-command/
