centos7 上在主機名變更新增了一個hostnamectl 指令 ，該指令的無論在輸出和更改上都較之前更加的便利。先看下hostname的help幫助信息：
[root@361way ~]# hostnamectl --help
hostnamectl [OPTIONS...] COMMAND ...
Query or change system hostname.
-h --help Show this help
--version Show package version
--transient Only set transient hostname
--static Only set static hostname
--pretty Only set pretty hostname
-P --privileged Acquire privileges before execution
--no-ask-password Do not prompt for password
-H --host=[USER@]HOST Operate on remote host
Commands:
status Show current hostname settings
set-hostname NAME Set system hostname
set-icon-name NAME Set icon name for host
set-chassis NAME Set chassis type for host
查看hostname信息
[root@361way ~]# hostnamectl
Static hostname: 361way
Icon name: computer-desktop
Chassis: desktop
Machine ID: 6917731f5fe447d0bca296ed2802e250
Boot ID: e0d20bc2a3a4474c960394967d33ab53
Operating System: CentOS Linux 7 (Core)
CPE OS Name: cpe:/o:centos:centos:7
Kernel: Linux 3.10.0-123.6.3.el7.x86_64
Architecture: x86_64
設置主機名
從上面的help 幫助里可以看到，在設置主機名時，這里涉及到四種主機名，在hostnamectl 的man手冊里給予了說明和解釋，如下：
This tool distinguishes three different hostnames: the high-level "pretty" hostname which might include all kinds of special characters (e.g. "Lennart's
Laptop"), the static hostname which is used to initialize the kernel hostname at boot (e.g. "lennarts-laptop"), and the transient hostname which might be
assigned temporarily due to network configuration and might revert back to the static hostname if network connectivity is lost and is only temporarily
written to the kernel hostname (e.g. "dhcp-47-11").
Note that the pretty hostname has little restrictions on the characters used, while the static and transient hostnames are limited to the usually accepted
characters of Internet domain names.
更改主機名
一般情況下都是使用set-hostname進行更改：
[root@361way ~]# hostnamectl set-hostname blog
更改主機名一般會涉及到/etc/hostname 、/etc/machine-info 兩個文件，同時對于不同的名字修改在man手冊上也給了說明：
The static hostname is stored in /etc/hostname, see hostname(5) for more information. The pretty hostname, chassis type, and icon name are stored in /etc/machine-info, see machine-id(5).
set-icon-name 設置的主機一般和圖形界面會用到，對應的hostnamectl 輸出中的Icon name ，set-chassis 指定了主機的平臺類型，如本機的是desktop，還可以設置為："desktop", "laptop", "server", "tablet", "handset"
