关机、重启：
立即关机：halt、poweroff、shutdown -h now
延迟关机：shutdown -h 10 十分钟后关机
立即重启：reboot、shutdown -r now
延迟重启：shutdown -r 10 十分钟后重启、shutdown -r 20:35 定点重启
取消：shutdown -c
Ubuntu14 版本查询
xzx@git:~$ lsb_release -a LSB是Linux Standard Base的缩写，lsb_release命令用来显示LSB和特定版本的相关信息 No LSB modules are available. Distributor ID: Ubuntu 类别是ubuntu Description: Ubuntu 14.04.6 LTS 16年3月发布的稳定版本，LTS是Long Term Support：长时间支持版本，支持周期长达三至五年 Release: 14.04 发行版本号 Codename: trusty ubuntu的代号名称
xzx@git:~$ uname -a 查看系统相关信息 Linux 内核名称git 主机名4.4.0-142-generic 内核发行号#168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 内核版本号x86_64 机器硬件名称，即操作系统位数x86_64 处理器类型x86_64 硬件平台GNU/Linux 操作系统
xzx@git:~$ cat /proc/version Linux version 4.4.0-142-generic (buildd@lcy01-amd64-006) linux内核版本号(gcc version 4.8.4 (Ubuntu 4.8.4-2ubuntu1~14.04.4) ) gcc编译器版本号、Ubuntu版本号#168~14.04.1-Ubuntu SMP Sat Jan 19 11:26:28 UTC 2019 内核版本号
Ubuntu14 重启
执行service networking restart 报错！（需要root权限才可以正常运行）xzx@git:~$ service networking restart stop: Rejected send message, 1 matched rules; type="method_call", sender=":1.14" (uid=1000 pid=1576 comm="stop networking ") interface="com.ubuntu.Upstart0_6.Job" member="Stop" error name="(unset)" requested_reply="0" destination="com.ubuntu.Upstart" (uid=0 pid=1 comm="/sbin/init ") 切换到root用户下，执行service networking restart，依然报错！Ubuntu14版已经不支持使用service对网络进行停止重启。 xzx@git:~$ su root Password: root@git:/home/xzx# service networking restart stop: Job failed while stopping start: Job is already running: networking 正确的使用方法：ifdown eth0 && ifup eth0 root@git:/home/xzx# ifdown eth0 && ifup eth0 Internet Systems Consortium DHCP Client 4.2.4 Copyright 2004-2012 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/08:00:27:ef:72:ec Sending on LPF/eth0/08:00:27:ef:72:ec Sending on Socket/fallback DHCPRELEASE on eth0 to 10.20.6.254 port 67 (xid=0x1e6a46a7) Internet Systems Consortium DHCP Client 4.2.4 Copyright 2004-2012 Internet Systems Consortium. All rights reserved. For info, please visit https://www.isc.org/software/dhcp/ Listening on LPF/eth0/08:00:27:ef:72:ec Sending on LPF/eth0/08:00:27:ef:72:ec Sending on Socket/fallback DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 3 (xid=0x828e5509) DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 5 (xid=0x828e5509) DHCPREQUEST of 10.20.6.185 on eth0 to 255.255.255.255 port 67 (xid=0x9558e82) DHCPOFFER of 10.20.6.185 from 10.20.6.254 DHCPACK of 10.20.6.185 from 10.20.6.254 bound to 10.20.6.185 -- renewal in 32751 seconds.