Solved "device eth0 does not seem to be present, delaying initialization"

This error is mostly observed due to changes in MAC address of the NIC card used in the Linux
For me it occurred when I cloned one of my Linux virtual machine. So the cloned machine was not able to detect the NIC and every time I tried to restart the network it was throwing this error.
Now when you clone a machine all the setting and default properties gets cloned from the original one including the hostname, IP address and MAC address which should be different for each machine as they are the one which helps you recognize machines on the network.
Now changing hostname and IP Address is quiet easy task but changing a MAC address is a bit tricky as you should know the MAC id of the new NIC installed.
The MAC id details for the NIC card is stored in the below mentioned file which is automatically created every time the machine boots.


If you open this file the contents would be like this

# less /etc/udev/rules.d/70-persistent-net.rules
# PCI device 0x1022:0x2000 (pcnet32) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50::56:8a:1f:32", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Delete this file

# rm -f /etc/udev/rules.d/70-persistent-net.rules

Reboot your machine as after reboot a new file will be created with the details of your new NIC card

# less /etc/udev/rules.d/70-persistent-net.rules
# PCI device 0x1022:0x2000 (pcnet32) SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:50:56:bb:72:20", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

As you can see the difference in MAC id and NIC card name
It is time for you to copy the new MAC id and NIC card name to your ifcfg-eth0 file

# vi /etc/sysconfig/network-scripts/ifcfg-eth0

Restart your network and everything should work fine
In case you want to use the same NIC name eth0 then replace the NIC card name from 70-persistent-net.rules file and reboot your machine for the changes to take affect