Device eth0 does not seem to be present, delaying initialization - Virtual Box Error - CentOS 6.6

Hello everyone,

Today I've faced an error on Virtual Box with CentOS 6.6 today, If you are frequently use virtual machines, you'll see these kind of errors. Let's explain my situation.

I've installed and used CentOS 6.6 for python before 2 months, later I've deleted it's account (not files) from Virtual Box because of no frequent use. Today I need to test something on that server. So I've created account and pointed this virtual machine to newly created account.

Once server up, logged to server and tried to ping for check the network. Network not succeeded, when I check IP with ifconfig, I can see only loopback network. "service network restart" says "Device eth0 does not seem to be present, delaying initialization".

Okay, What is solution now ?

Reason for this issue: When we install guest OS with virtual box, It'll assign mac address to it's guest OS's device. But in our case, we have installed guest OS already and it already assigned some mac address. When we create account again and merge guest OS with it, we will get conflict with 2 different mac address. One was created during original installation of guest OS, another one is created during recreate of virtualbox guest OS account.

To fix this,

Login to OS, remove the file as mentioned bellow, which have old mac address.

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

Reboot server, so that new fill will be generated again,

# reboot

Now open the file,
# cat /etc/udev/rules.d/70-persistent-net.rules

It'll look as mentioned bellow,

# This file was automatically generated by the /lib/udev/write_net_rules
# program, run by the persistent-net-generator.rules rules file.
#
# You can modify it, as long as you keep each rule on a single
# line, and change only the value of the NAME= key.

# PCI device 0x8086:0x100e (e1000)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="08:00:17:ef:c5:08", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"

Note down the ATTR{address}

open following file

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

Replace mac address which you copied to HWADDR
Remove line with UUID

Now restart the network service,

# service network restart

That's It. Now you can able access network on guest OS.