Systemd 与 Systemctl 命令指南
2015-10-09 13:11
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Systemd 与 Systemctl 命令指南
http://blog.csdn.net/Well_Im/article/details/48946809?ref=myread在 Linux 生态系统中，Systemd 被部署到了大多数的标准 Linux 发行版中，只有为数不多的几个发行版尚未部署。Systemd 通常是所有其它守护进程的父进程，但并非总是如此。
Systemctl 是一个 systemd 工具，主要负责控制 systemd 系统和服务管理器。
Systemd 是一个系统管理守护进程、工具和库的集合，用于取代 System V 初始进程。Systemd 的功能是用于集中管理和配置类 UNIX 系统。
本文旨在阐明如何运用 systemd 的系统来控制系统和服务。
Systemd初体验和Systemctl基础
首先检查你的系统中是否安装有systemd并确定当前安装的版本
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd --version</span> systemd <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">215</span> +PAM +AUDIT +SELINUX +IMA +SYSVINIT +LIBCRYPTSETUP +GCRYPT +ACL +XZ -SECCOMP -APPARMOR</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
上例中很清楚地表明，我们安装了215版本的systemd。
检查systemd和systemctl的二进制文件和库文件的安装位置
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># whereis systemd</span> systemd: /usr/lib/systemd /etc/systemd /usr/share/systemd /usr/share/man/man1/systemd.<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>.gz <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># whereis systemctl</span> systemctl: /usr/bin/systemctl /usr/share/man/man1/systemctl.<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>.gz</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
检查systemd是否运行
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># ps -eaf | grep [s]ystemd</span> root <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span> /usr/lib/systemd/systemd --switched-root --system --deserialize <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">23</span> root <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">444</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span> /usr/lib/systemd/systemd-journald root <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">469</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span> /usr/lib/systemd/systemd-udevd root <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">555</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span> /usr/lib/systemd/systemd-logind dbus <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">556</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span> ? <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span> /bin/dbus-daemon --system --address=systemd: --nofork --nopidfile --systemd-activation</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li></ul>
注意：systemd是作为父进程（PID=1）运行的。在上面带（-e）参数的ps命令输出中，选择所有进程，（-a）选择除会话前导外的所有进程，并使用（-f）参数输出完整格式列表（即 -eaf）。
也请注意上例中后随的方括号和例子中剩余部分。方括号表达式是grep的字符类表达式的一部分。
分析systemd启动进程
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-analyze</span> Startup finished <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">in</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">487</span>ms (kernel) + <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2.776</span>s (initrd) + <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20.229</span>s (userspace) = <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">23.493</span>s</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
分析启动时各个进程花费的时间
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-analyze blame</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.565</span>s mariadb.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7.991</span>s webmin.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6.095</span>s postfix.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.311</span>s httpd.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.926</span>s firewalld.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.780</span>s kdump.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.238</span>s tuned.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.712</span>s network.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.394</span>s lvm2-monitor.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.126</span>s systemd-logind.service ....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>
分析启动时的关键链
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-analyze critical-chain</span> The time after the unit is active or started is printed after the <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"@"</span> character. The time the unit takes to start is printed after the <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"+"</span> character. multi-user.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">20.222</span>s └─mariadb.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.657</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.565</span>s └─network.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.168</span>s └─network.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9.456</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.712</span>s └─NetworkManager.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.858</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">596</span>ms └─firewalld.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.931</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.926</span>s └─basic.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─sockets.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─dbus.socket @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─sysinit.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.905</span>s └─systemd-update-utmp.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.864</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">39</span>ms └─auditd.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.563</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">301</span>ms └─systemd-tmpfiles-setup.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.485</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">69</span>ms └─rhel-import-state.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.342</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">142</span>ms └─local-fs.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.324</span>s └─boot.mount @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.286</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>ms └─systemd-fsck@dev-disk-by\x2duuid-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79</span>f594ad\x2da332\x2d4730\x2dbb5f\x2d85d19608096 └─dev-disk-by\x2duuid-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79</span>f594ad\x2da332\x2d4730\x2dbb5f\x2d85d196080964.device @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li></ul>
重要：Systemctl接受服务（.service），挂载点（.mount），套接口（.socket）和设备（.device）作为单元。
列出所有可用单元
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-unit-files</span> UNIT FILE STATE proc-sys-fs-binfmt_misc.automount static dev-hugepages.mount static dev-mqueue.mount static proc-sys-fs-binfmt_misc.mount static sys-fs-fuse-connections.mount static sys-kernel-config.mount static sys-kernel-debug.mount static tmp.mount disabled brandbot.path disabled .....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li></ul>
列出所有运行中单元
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-units</span> UNIT LOAD ACTIVE SUB DESCRIPTION proc-sys-fs-binfmt_misc.automount loaded active waiting Arbitrary Executable File Formats File Syste sys-devices-pc...<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>-block-sr0.device loaded active plugged VBOX_CD-ROM sys-devices-pc...:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">03.0</span>-net-enp0s3.device loaded active plugged PRO/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1000</span> MT Desktop Adapter sys-devices-pc...<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">00</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">05.0</span>-sound-card0.device loaded active plugged <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">82801</span>AA AC<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'97 Audio Controller sys-devices-pc...:0:0-block-sda-sda1.device loaded active plugged VBOX_HARDDISK sys-devices-pc...:0:0-block-sda-sda2.device loaded active plugged LVM PV Qzyo3l-qYaL-uRUa-Cjuk-pljo-qKtX-VgBQ8 sys-devices-pc...0-2:0:0:0-block-sda.device loaded active plugged VBOX_HARDDISK sys-devices-pl...erial8250-tty-ttyS0.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS0 sys-devices-pl...erial8250-tty-ttyS1.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS1 sys-devices-pl...erial8250-tty-ttyS2.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS2 sys-devices-pl...erial8250-tty-ttyS3.device loaded active plugged /sys/devices/platform/serial8250/tty/ttyS3 sys-devices-virtual-block-dm\x2d0.device loaded active plugged /sys/devices/virtual/block/dm-0 sys-devices-virtual-block-dm\x2d1.device loaded active plugged /sys/devices/virtual/block/dm-1 sys-module-configfs.device loaded active plugged /sys/module/configfs ....</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li></ul>
列出所有失败单元
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl --failed</span> UNIT LOAD ACTIVE SUB DESCRIPTION kdump.service loaded failed failed Crash recovery kernel arming LOAD = Reflects whether the unit definition was properly loaded. ACTIVE = The high-level unit activation state, i.e. generalization of SUB. SUB = The low-level unit activation state, values depend on unit type. <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> loaded units listed. Pass --all to see loaded but inactive units, too. To show all installed unit files use <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'systemctl list-unit-files'</span>.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li></ul>
检查某个单元（如 cron.service）是否启用
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl is-enabled crond.service</span> enabled</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
检查某个单元或服务是否运行
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl status firewalld.service</span> firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; enabled) Active: active (running) since Tue <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">55</span> IST; <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">34</span>min ago Main PID: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">549</span> (firewalld) CGroup: /system.slice/firewalld.service └─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">549</span> /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">51</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Starting firewalld - dynamic firewall daemon... Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">16</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">27</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">55</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Started firewalld - dynamic firewall daemon.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>
使用Systemctl控制并管理服务
列出所有服务（包括启用的和禁用的）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-unit-files --type=service</span> UNIT FILE STATE arp-ethers.service disabled auditd.service enabled autovt@.service disabled blk-availability.service disabled brandbot.service static collectd.service disabled console-getty.service disabled console-shell.service disabled cpupower.service disabled crond.service enabled dbus-org.fedoraproject.FirewallD1.service enabled ....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>
Linux中如何启动、重启、停止、重载服务以及检查服务(如 httpd.service)状态
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl start httpd.service</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl restart httpd.service</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl stop httpd.service</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl reload httpd.service</span>
<span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl status httpd.service</span>
httpd.service - The Apache HTTP Server
Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled)
Active: active (running) since Tue <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span> IST; <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span>s ago
Process: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2876</span> ExecStop=/bin/kill -WINCH <span class="hljs-variable" style="color: rgb(102, 0, 102); box-sizing: border-box;">${MAINPID}</span> (code=exited, status=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>/SUCCESS)
Main PID: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span> (httpd)
Status: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Processing requests..."</span>
CGroup: /system.slice/httpd.service
├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span> /usr/sbin/httpd -DFOREGROUND
├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2884</span> /usr/sbin/httpd -DFOREGROUND
├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2885</span> /usr/sbin/httpd -DFOREGROUND
├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2886</span> /usr/sbin/httpd -DFOREGROUND
├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2887</span> /usr/sbin/httpd -DFOREGROUND
└─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2888</span> /usr/sbin/httpd -DFOREGROUND
Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Starting The Apache HTTP Server...
Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">21</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">30</span> tecmint httpd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>]: AH00558: httpd: Could not reliably determine the server<span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'s fully q...ssage
Apr 28 17:21:30 tecmint systemd[1]: Started The Apache HTTP Server.
Hint: Some lines were ellipsized, use -l to show in full.</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li></ul>
如何激活服务并在启动时启用或禁用服务（即系统启动时自动启动服务）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl is-active httpd.service</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl enable httpd.service</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl disable httpd.service</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
如何屏蔽（让它不能启动）或显示服务（如 httpd.service）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl mask httpd.service</span> ln <span class="hljs-operator" style="box-sizing: border-box;">-s</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/dev/null'</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/httpd.service'</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl unmask httpd.service</span> rm <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/httpd.service'</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
使用systemctl命令杀死服务
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl kill httpd</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl status httpd</span> httpd.service - The Apache HTTP Server Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled) Active: failed (Result: <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">exit</span>-code) since Tue <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">01</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">42</span> IST; <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span>min ago Main PID: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span> (code=exited, status=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>/SUCCESS) Status: <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"Total requests: 0; Current requests/sec: 0; Current traffic: 0 B/sec"</span> Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">29</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">29</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">39</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">39</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">49</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">49</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">37</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: Got notification message from PID <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2881</span>, but recepti...bled. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">01</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">42</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: httpd.service: control process exited, code=exited status=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">226</span> Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">01</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">42</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Unit httpd.service entered failed state. Hint: Some lines were ellipsized, use <span class="hljs-operator" style="box-sizing: border-box;">-l</span> to show <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">in</span> full.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>
使用Systemctl控制并管理挂载点
列出所有系统挂载点
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-unit-files --type=mount</span> UNIT FILE STATE dev-hugepages.mount static dev-mqueue.mount static proc-sys-fs-binfmt_misc.mount static sys-fs-fuse-connections.mount static sys-kernel-config.mount static sys-kernel-debug.mount static tmp.mount disabled</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li></ul>
挂载、卸载、重新挂载、重载系统挂载点并检查系统中挂载点状态
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl start tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl stop tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl restart tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl reload tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl status tmp.mount</span> tmp.mount - Temporary Directory Loaded: loaded (/usr/lib/systemd/system/tmp.mount; disabled) Active: active (mounted) since Tue <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">46</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">06</span> IST; <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span>min <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">48</span>s ago Where: /tmp What: tmpfs Docs: man:hier(<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">7</span>) http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems Process: <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3908</span> ExecMount=/bin/mount tmpfs /tmp -t tmpfs -o mode=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1777</span>,strictatime (code=exited, status=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>/SUCCESS) Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">46</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">06</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Mounting Temporary Directory... Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">46</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">06</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: tmp.mount: Directory /tmp to mount over is not empty, mounting anyway. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">17</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">46</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">06</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Mounted Temporary Directory.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>
在启动时激活、启用或禁用挂载点（系统启动时自动挂载）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl is-active tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl enable tmp.mount</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl disable tmp.mount</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
在Linux中屏蔽（让它不能启用）或可见挂载点
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl mask tmp.mount</span> ln <span class="hljs-operator" style="box-sizing: border-box;">-s</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/dev/null'</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/tmp.mount'</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl unmask tmp.mount</span> rm <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/tmp.mount'</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
使用Systemctl控制并管理套接口
列出所有可用系统套接口
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-unit-files --type=socket</span> UNIT FILE STATE dbus.socket static dm-event.socket enabled lvm2-lvmetad.socket enabled rsyncd.socket disabled sshd.socket disabled syslog.socket static systemd-initctl.socket static systemd-journald.socket static systemd-shutdownd.socket static systemd-udevd-control.socket static systemd-udevd-kernel.socket static <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span> unit files listed.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li></ul>
在Linux中启动、重启、停止、重载套接口并检查其状态
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl start cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl restart cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl stop cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl reload cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl status cups.socket</span> cups.socket - CUPS Printing Service Sockets Loaded: loaded (/usr/lib/systemd/system/cups.socket; enabled) Active: active (listening) since Tue <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> IST; <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8</span>s ago Listen: /var/run/cups/cups.sock (Stream) Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Starting CUPS Printing Service Sockets. Apr <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">28</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">10</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">59</span> tecmint systemd[<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>]: Listening on CUPS Printing Service Sockets.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li></ul>
在启动时激活套接口，并启用或禁用它（系统启动时自启动）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl is-active cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl enable cups.socket</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl disable cups.socket</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
屏蔽（使它不能启动）或显示套接口
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl mask cups.socket</span> ln <span class="hljs-operator" style="box-sizing: border-box;">-s</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/dev/null'</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/cups.socket'</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl unmask cups.socket</span> rm <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">'/etc/systemd/system/cups.socket'</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
服务的CPU利用率（分配额）
获取当前某个服务的CPU分配额（如httpd）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl show -p CPUShares httpd.service</span> CPUShares=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1024</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
注意：各个服务的默认CPU分配份额=1024，你可以增加/减少某个进程的CPU分配份额。
将某个服务（httpd.service）的CPU分配份额限制为2000 CPUShares/
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl set-property httpd.service CPUShares=2000</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl show -p CPUShares httpd.service</span> CPUShares=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
注意：当你为某个服务设置CPUShares，会自动创建一个以服务名命名的目录（如 httpd.service），里面包含了一个名为90-CPUShares.conf的文件，该文件含有CPUShare限制信息，你可以通过以下方式查看该文件：
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># vi /etc/systemd/system/httpd.service.d/90-CPUShares.conf </span> [Service] CPUShares=<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2000</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
检查某个服务的所有配置细节
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl show httpd</span> Id=httpd.service Names=httpd.service Requires=basic.target Wants=system.slice WantedBy=multi-user.target Conflicts=shutdown.target Before=shutdown.target multi-user.target After=network.target remote-fs.target nss-lookup.target systemd-journald.socket basic.target system.slice Description=The Apache HTTP Server LoadState=loaded ActiveState=active SubState=running FragmentPath=/usr/lib/systemd/system/httpd.service ....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li></ul>
分析某个服务（httpd）的关键链
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-analyze critical-chain httpd.service</span> The time after the unit is active or started is printed after the <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"@"</span> character. The time the unit takes to start is printed after the <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"+"</span> character. httpd.service +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">142</span>ms └─network.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11.168</span>s └─network.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">9.456</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.712</span>s └─NetworkManager.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">8.858</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">596</span>ms └─firewalld.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.931</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3.926</span>s └─basic.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─sockets.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─dbus.socket @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.916</span>s └─sysinit.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.905</span>s └─systemd-update-utmp.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.864</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">39</span>ms └─auditd.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.563</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">301</span>ms └─systemd-tmpfiles-setup.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.485</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">69</span>ms └─rhel-import-state.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.342</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">142</span>ms └─local-fs.target @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.324</span>s └─boot.mount @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.286</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>ms └─systemd-fsck@dev-disk-by\x2duuid-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79</span>f594ad\x2da332\x2d4730\x2dbb5f\x2d85d196080964.service @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.092</span>s +<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">149</span>ms └─dev-disk-by\x2duuid-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">79</span>f594ad\x2da332\x2d4730\x2dbb5f\x2d85d196080964.device @<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4.092</span>s</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>
获取某个服务（httpd）的依赖性列表
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl list-dependencies httpd.service</span> httpd.service ├─system.slice └─basic.target ├─firewalld.service ├─microcode.service ├─rhel-autorelabel-mark.service ├─rhel-autorelabel.service ├─rhel-configure.service ├─rhel-dmesg.service ├─rhel-loadmodules.service ├─paths.target ├─slices.target │ ├─-.slice │ └─system.slice ├─sockets.target │ ├─dbus.socket ....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li></ul>
按等级列出控制组
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-cgls</span> ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> /usr/lib/systemd/systemd --switched-root --system --deserialize <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">23</span> ├─user.slice │ └─user-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>.slice │ └─session-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>.scope │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2498</span> sshd: root@pts/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2500</span> -bash │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4521</span> systemd-cgls │ └─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4522</span> systemd-cgls └─system.slice ├─httpd.service │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4440</span> /usr/sbin/httpd -DFOREGROUND │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4442</span> /usr/sbin/httpd -DFOREGROUND │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4443</span> /usr/sbin/httpd -DFOREGROUND │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4444</span> /usr/sbin/httpd -DFOREGROUND │ ├─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4445</span> /usr/sbin/httpd -DFOREGROUND │ └─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">4446</span> /usr/sbin/httpd -DFOREGROUND ├─polkit.service │ └─<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">721</span> /usr/lib/polkit-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>/polkitd --no-debug ....</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li></ul>
按CPU、内存、输入和输出列出控制组
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemd-cgtop</span> Path Tasks %CPU Memory Input/s Output/s / <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">83</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1.0</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">437.8</span>M - - /system.slice - <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.1</span> - - - /system.slice/mariadb.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.1</span> - - - /system.slice/tuned.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span> - - - /system.slice/httpd.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">6</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0.0</span> - - - /system.slice/NetworkManager.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/atop.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/atopacct.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/auditd.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/crond.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/dbus.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/firewalld.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/lvm2-lvmetad.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/polkit.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/postfix.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> - - - - /system.slice/rsyslog.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/system-getty.slice/getty@tty1.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/systemd-journald.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/systemd-logind.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/systemd-udevd.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /system.slice/webmin.service <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span> - - - - /user.slice/user-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span>.slice/session-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">1</span>.scope <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">3</span> - - - -</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li><li style="box-sizing: border-box; padding: 0px 5px;">6</li><li style="box-sizing: border-box; padding: 0px 5px;">7</li><li style="box-sizing: border-box; padding: 0px 5px;">8</li><li style="box-sizing: border-box; padding: 0px 5px;">9</li><li style="box-sizing: border-box; padding: 0px 5px;">10</li><li style="box-sizing: border-box; padding: 0px 5px;">11</li><li style="box-sizing: border-box; padding: 0px 5px;">12</li><li style="box-sizing: border-box; padding: 0px 5px;">13</li><li style="box-sizing: border-box; padding: 0px 5px;">14</li><li style="box-sizing: border-box; padding: 0px 5px;">15</li><li style="box-sizing: border-box; padding: 0px 5px;">16</li><li style="box-sizing: border-box; padding: 0px 5px;">17</li><li style="box-sizing: border-box; padding: 0px 5px;">18</li><li style="box-sizing: border-box; padding: 0px 5px;">19</li><li style="box-sizing: border-box; padding: 0px 5px;">20</li><li style="box-sizing: border-box; padding: 0px 5px;">21</li><li style="box-sizing: border-box; padding: 0px 5px;">22</li><li style="box-sizing: border-box; padding: 0px 5px;">23</li><li style="box-sizing: border-box; padding: 0px 5px;">24</li></ul>
控制系统运行等级
启动系统救援模式
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl rescue</span> Broadcast message from root@tecmint on pts/<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">0</span> (Wed <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">2015</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">04</span>-<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">29</span> <span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">11</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">31</span>:<span class="hljs-number" style="color: rgb(0, 102, 102); box-sizing: border-box;">18</span> IST): The system is going down to rescue mode NOW!</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
进入紧急模式
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl emergency</span> Welcome to emergency mode! After logging <span class="hljs-keyword" style="color: rgb(0, 0, 136); box-sizing: border-box;">in</span>, <span class="hljs-built_in" style="color: rgb(102, 0, 102); box-sizing: border-box;">type</span> <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"journalctl -xb"</span> to view system logs, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"systemctl reboot"</span> to reboot, <span class="hljs-string" style="color: rgb(0, 136, 0); box-sizing: border-box;">"systemctl default"</span> to try again to boot into default mode.</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li></ul>
列出当前使用的运行等级
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl get-default</span> multi-user.target</code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
启动运行等级5，即图形模式
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl isolate runlevel5.target</span> 或 <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl isolate graphical.target</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
启动运行等级3，即多用户模式（命令行）
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl isolate runlevel3.target</span> 或 <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl isolate multiuser.target</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li></ul>
设置多用户模式或图形模式为默认运行等级
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl set-default runlevel3.target</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl set-default runlevel5.target</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li></ul>
重启、停止、挂起、休眠系统或使系统进入混合睡眠
<code class="language-bash hljs has-numbering" style="display: block; padding: 0px; color: inherit; box-sizing: border-box; font-family: 'Source Code Pro', monospace;font-size:undefined; white-space: pre; border-radius: 0px; word-wrap: normal; background: transparent;"> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl reboot</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl halt</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl suspend</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl hibernate</span> <span class="hljs-comment" style="color: rgb(136, 0, 0); box-sizing: border-box;"># systemctl hybrid-sleep</span></code><ul class="pre-numbering" style="box-sizing: border-box; position: absolute; width: 50px; top: 0px; left: 0px; margin: 0px; padding: 6px 0px 40px; border-right-width: 1px; border-right-style: solid; border-right-color: rgb(221, 221, 221); list-style: none; text-align: right; background-color: rgb(238, 238, 238);"><li style="box-sizing: border-box; padding: 0px 5px;">1</li><li style="box-sizing: border-box; padding: 0px 5px;">2</li><li style="box-sizing: border-box; padding: 0px 5px;">3</li><li style="box-sizing: border-box; padding: 0px 5px;">4</li><li style="box-sizing: border-box; padding: 0px 5px;">5</li></ul>
对于不知运行等级为何物的人，说明如下。
Runlevel 0 : 关闭系统
Runlevel 1 : 救援？维护模式
Runlevel 3 : 多用户，无图形系统
Runlevel 4 : 多用户，无图形系统
Runlevel 5 : 多用户，图形化系统
Runlevel 6 : 关闭并重启机器
到此为止吧。保持连线，进行评论。别忘了在下面的评论中为我们提供一些有价值的反馈哦。喜欢我们、与我们分享，求扩散。
via: http://www.tecmint.com/manage-services-using-systemd-and-systemctl-in-linux/
作者：Avishek Kumar 译者：GOLinux 校对：wxy
本文由 LCTT 原创翻译，Linux中国 荣誉推出
来源：/article/1318479.html
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