centos系统中，如果/sbin目录下没有service这个命令，就会出现
-bash: service: command not found
的错误。
解决步骤如下：
1、输入：
# yum list | grep initscripts会出现：
initscripts.x86_64 9.49.30-1.el7_2.3 updates
2、上面给出了可安装软件的yum源版本。
上面是目前系统已安装的initscripts情况，因为没有了service文件，显然已经出现了错误，然后执行
# yum install initscripts
会显示
Loaded plugins: fastestmirror
Loading mirror speeds from cached hostfile
* base: mirrors.btte.net
* extras: mirrors.tuna.tsinghua.edu.cn
* updates: mirrors.btte.net
Resolving Dependencies
--> Running transaction check
---> Package initscripts.x86_64 0:9.49.30-1.el7_2.3 will be installed
--> Processing Dependency: iproute for package: initscripts-9.49.30-1.el7_2.3.x86_64
--> Running transaction check
---> Package iproute.x86_64 0:3.10.0-54.el7_2.1 will be installed
--> Processing Dependency: libxtables.so.10()(64bit) for package: iproute-3.10.0-54.el7_2.1.x86_64
--> Running transaction check
---> Package iptables.x86_64 0:1.4.21-16.el7 will be installed
--> Finished Dependency Resolution
Dependencies Resolved
===================================================================================================
Package Arch Version Repository Size
===================================================================================================
Installing:
initscripts x86_64 9.49.30-1.el7_2.3 updates 429 k
Installing for dependencies:
iproute x86_64 3.10.0-54.el7_2.1 updates 526 k
iptables x86_64 1.4.21-16.el7 base 424 k
Transaction Summary
===================================================================================================
Install 1 Package (+2 Dependent packages)
Total download size: 1.3 M
Installed size: 4.2 M
Is this ok [y/d/N]: y
Downloading packages:
(1/3): iproute-3.10.0-54.el7_2.1.x86_64.rpm | 526 kB 00:00:00
(2/3): initscripts-9.49.30-1.el7_2.3.x86_64.rpm | 429 kB 00:00:00
(3/3): iptables-1.4.21-16.el7.x86_64.rpm | 424 kB 00:00:00
---------------------------------------------------------------------------------------------------
Total 1.7 MB/s | 1.3 MB 00:00:00
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Installing : iptables-1.4.21-16.el7.x86_64 1/3
Installing : iproute-3.10.0-54.el7_2.1.x86_64 2/3
Installing : initscripts-9.49.30-1.el7_2.3.x86_64 3/3
Verifying : iptables-1.4.21-16.el7.x86_64 1/3
Verifying : iproute-3.10.0-54.el7_2.1.x86_64 2/3
Verifying : initscripts-9.49.30-1.el7_2.3.x86_64 3/3
Installed:
initscripts.x86_64 0:9.49.30-1.el7_2.3
Dependency Installed:
iproute.x86_64 0:3.10.0-54.el7_2.1 iptables.x86_64 0:1.4.21-16.el7
Complete!
3、此时service已经可以使用。
附加：
如果还出现
bash: service: command not found
这个错误。两种方式解决：
两种方式：
a、直接使用su - root来切换到root用户，然后使用 service
b、使用su root切换到root用户，并同时使用/sbin/service来操作，如/sbin/service mysql restart.