1、在grub里增加biosdevname=0的启动参数，形如
kernel /vmlinuz-2.6.32-131.21.1.el6.i686 ro root=/dev/mapper/vg_test-lv_root rd_LVM_LV=vg_test/lv_root rd_LVM_LV=vg_test/lv_swap rd_NO_LUKS rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latar
cyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet biosdevname=0
步骤：
首先cd /etc/sysconfig/network-scripts或者vi /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda2
# initrd /initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-220.17.1.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-220.17.1.el6.x86_64 ro root=UUID=41d8fd59-98cb-44fa-9cfb-065c104feaf0 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarc
yrheb-sun16 rhgb crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM
biosdevname=0
initrd /initramfs-2.6.32-220.17.1.el6.x86_64.img
title CentOS (2.6.32-220.el6.x86_64)
root (hd0,0)
kernel /vmlinuz-2.6.32-220.el6.x86_64 ro root=UUID=41d8fd59-98cb-44fa-9cfb-065c104feaf0 rd_NO_LUKS rd_NO_LVM LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb
-sun16 rhgb crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM
biosdevname=0
initrd /initramfs-2.6.32-220.el6.x86_64.img
添加的参数只有红色字体的那一段，然后保存文件
2、删除udev的配置文件rm -f /etc/udev/rules.d/70-persistent-net.rules
3、把网卡配置文件改名
第三步：修改当前网卡配置文件的名称
mv ifcfg-em1 ifcfg-eth0
mv ifcfg-em2 ifcfg-eth1
mv ifcfg-em3 ifcfg-eth2
mv ifcfg-em4 ifcfg-eth3
mv ifcfg-em1 ifcfg-eth0
4、把网卡配置文件内容修正，把em1的全部改成eth0
perl -p -i -e ‘s/em1/eth0/g’ ifcfg-eth0
或者
修改之前：
DEVICE="em1"
NM_CONTROLLED="yes"
ONBOOT=yes
HWADDR=D4:AE:52:6A:8F:76
TYPE=Ethernet
BOOTPROTO=none
IPADDR=114.X.X.X
GATEWAY=114.X.X.X
NETMAKS=255.255.255.224
DNS1=202.106.0.20
DNS2=8.8.8.8
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
修改之后：
DEVICE="eth0"
NM_CONTROLLED="yes"
ONBOOT=yes
HWADDR=D4:AE:52:6A:8F:76
TYPE=Ethernet
BOOTPROTO=none
IPADDR=114.X.X.X
GATEWAY=114.X.X.X
NETMAKS=255.255.255.224
DNS1=202.106.0.20
DNS2=8.8.8.8
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
可以使用 perl -p -i -e 's/em1/eth0/g' ifcfg-eth0 或sed -i 's/em1/eth0/g' ifcfg-eth0 进行替换。
最后一步：重新启动系统 init 6 启动之后你就发现熟悉的eth0-eth4已经回来啦，顺便说下centos 6.2 还有一个问题就是如果你没有在网卡配置文件里写dns的话，重启之后你就会发现 /etc/resolv.conf 文件被清空了，一个方法就是在网卡配置文件中写DNS，另一个方法就是给/etc/resolv.conf加i属性，chattr +i /etc/resolv.conf
5、重启系统即可