When you copied a CentOS VM and boot it up,
after command in ifconfig
You'll found the your ethernet is not working.
and if you try to bring it up,
service network restart
response will be like below...
device eth0 does not seem to be present delaying initialization
The solution:
1. ifconfig -a
2. record your new MAC ADDRESS
(since you copied the vm, macaddr would not be the same with origin one.)
3. vim /etc/udev/rules.d/70-persistent-net.rules
4. modify the ATTR{address} to the recorded one in eth* which you're using
5. vim /etc/sysconfig/network-scripts/ifcfg-eth*
6. modify the HWADDR to the recorded one
7. service network restart