公司测试环境安装的都是RHEL6.3，在进行虚拟机克隆后，发现clone的虚拟机网卡起不来，具体报如下错误：
[root@localhost Desktop]# service network restart
Shutting down loopback interface: [ OK ]
Bringing up loopback interface: [ OK ]
Bringing up interface eth0: Error: No suitable device found: no device found for connection 'System eth0'.
[FAILED]
当你执行ifconfig命令的时候，会发现显示eth1网卡的配置文件却为/etc/sysconfig/network-scripts/ifcfg-eth0。
[root@localhost network-scripts]# ifconfig|grep addr
eth1 Link encap:Ethernet HWaddr 00:0c:29:f4:95:e3
inet6 addr: fe80::20c:29ff:fe5c:65b7/64 Scope:Link
Interrupt:19 Base address:0x2024
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
[root@localhost network-scripts]# ls
ifcfg-eth0 ifdown-isdn ifup-aliases ifup-plusb init.ipv6-global
ifcfg-lo ifdown-post ifup-bnep ifup-post net.hotplug
ifdown ifdown-ppp ifup-eth ifup-ppp network-functions
ifdown-bnep ifdown-routes ifup-ippp ifup-routes network-functions-ipv6
ifdown-eth ifdown-sit ifup-ipv6 ifup-sit
ifdown-ippp ifdown-tunnel ifup-isdn ifup-tunnel
ifdown-ipv6 ifup ifup-plip ifup-wireless
[root@localhost network-scripts]#
产生这个问题的原因是虚拟机分配给操作系统的虚拟网卡MAC地址是不一样的。第一个系统的网卡MAC地址记录在了/etc/udev/rules.d/70-persistent-net.rules，命名为eth0。新克隆分配的系统的网卡MAC地址也记录在了该文件当中，与之前的系统一样，因此有了冲突。
可以查看一下两个机子的这个70-persistent-net.rules文件的内容
第一个系统：
[root@localhost rules.d]# cat 70-persistent-net.rules
# 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 0x1022:0x2000 (pcnet32)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:f4:95:e3", ATTR{type}=="1", KERNEL=="eth*",
克隆后的系统：
[root@localhost rules.d]# cat 70-persistent-net.rules
# 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 0x1022:0x2000 (pcnet32)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:f4:95:e3", ATTR{type}=="1", KERNEL=="eth*",