參考：http://tieba.baidu.com/p/3233996339#57290767555l
在CentOS中配置靜態IP后不生效。
解決辦法：將/etc/sysconfig/network-scripts/ifcfg-eth0文件中的DEVICE=eth0注釋掉
解決過程：
一開始，配置文件/etc/sysconfig/network-scripts/ifcfg-eth0內容如下：
TYPE=Ethernet PROXY_METHOD=none BROWSER_ONLY=no BOOTPROTO=static DEFROUTE=yes NM_CONTROLLED="no" IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=eth0 DEVICE=eth0 ONBOOT=yes IPADDR=192.168.30.140 NETMASK=255.255.255.0 GETWAY=192.168.1.1 DNS1=114.114.114.114
試了網上其他人說的方法，比如
方法1. 禁用NetworkManager
systemctl stop NetworkManager
systemctl disable NetworkManager
方法2. 在/etc/sysconfig/network-scripts/ifcfg-eth0文件中設置
NM_CONTROLLED="no"
還試了其他一些方法，都沒用。而且發現使用 systemctl restart network報錯：
[root@node05 ~]# systemctl restart network
Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details.
[root@node05 ~]# systemctl status network
● network.service - LSB: Bring up/down networking
Loaded: loaded (/etc/rc.d/init.d/network; bad; vendor preset: disabled)
Active: failed (Result: exit-code) since Fri 2019-04-26 09:03:05 EDT; 8s ago
Docs: man:systemd-sysv-generator(8)
Process: 9950 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=1/FAILURE)
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 network[9950]: RTNETLINK answers: File exists
Apr 26 09:03:05 node05 systemd[1]: network.service: control process exited, code=exited status=1
Apr 26 09:03:05 node05 systemd[1]: Failed to start LSB: Bring up/down networking.
Apr 26 09:03:05 node05 systemd[1]: Unit network.service entered failed state.
Apr 26 09:03:05 node05 systemd[1]: network.service failed.
最終在貼吧里看到將DEVICE=eth0注釋掉的方法，試了一下，靜態IP生效了，但是systemctl restart network仍然報錯。原因未知。。。。反正靜態IP配置好了，但是浪費了好多時間。。。
2019/4/27 把DEVICE注釋掉后不能聯網了，why....
2019/5/17 將路由地址，默認網關，DNS配置好可解決大部分配置靜態地址后不能上網的問題。
eg.
[root@node04 test]# ifconfig ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.30.139 netmask 255.255.255.0 broadcast 192.168.30.255 inet6 fe80::3711:f55c:b51d:9cc7 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:f3:da:5a txqueuelen 1000 (Ethernet) RX packets 163813 bytes 21019361 (20.0 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 197627 bytes 24532180 (23.3 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 63821 bytes 9132036 (8.7 MiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 63821 bytes 9132036 (8.7 MiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
[root@node04 test]# route Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface default gateway 0.0.0.0 UG 100 0 0 ens33 192.168.30.0 0.0.0.0 255.255.255.0 U 100 0 0 ens33
[root@node04 network-scripts]# pwd /etc/sysconfig/network-scripts
[root@node04 network-scripts]# cat ifcfg-eth0 TYPE=Ethernet PROXY_METHOD=none BROWSER_ONLY=no BOOTPROTO=static DEFROUTE=yes IPV4_FAILURE_FATAL=no IPV6INIT=yes IPV6_AUTOCONF=yes IPV6_DEFROUTE=yes IPV6_FAILURE_FATAL=no IPV6_ADDR_GEN_MODE=stable-privacy NAME=eth0 DEVICE=eth0 ONBOOT=yes IPADDR=192.168.30.138 NETMASK=255.255.255.0 GETWAY=192.168.1.1 DNS1=114.114.114.114