CentOS6.5 重启网络报错：
Bringing up interface eth0: Error: Connection activation failed: Device not managed by NetworkManager or unavailable
解决方法：
[root@localhost network-scripts]# vi ifcfg-eth0
[root@localhost network-scripts]# service network restart
Shutting down interface eth0: [ OK ]
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: Error: Connection activation failed: Device not managed by NetworkManager or unavailable
[FAILED]
[root@localhost network-scripts]# cd /
[root@localhost /]# chkconfig NetworkManager off
[root@localhost /]# chkconfig network on
[root@localhost /]# service NetworkManager stop
Stopping NetworkManager daemon: [ OK ]
[root@localhost /]# service network start
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: [ OK ]
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
RTNETLINK answers: File exists
[root@localhost /]# service network restart
Shutting down interface eth0: [ OK ]
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: Determining if ip address 192.168.20.26 is already in use for device eth0...
[ OK ]
[root@localhost /]#