kvm 虚拟机 复制之后 默认网卡是 eth2了
用 ifconfig -a 命令查看所有的网络设置，果然没有eth0的相关设置，多出来一个eth2。显示如下：
[root@neal ~]# ifconfig -a
eth2 Link encap:Ethernet HWaddr 52:54:00:A0:10:38
inet addr:192.168.1.226 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::5054:ff:fea0:1038/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:11764 errors:0 dropped:0 overruns:0 frame:0
TX packets:5302 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1361989 (1.2 MiB) TX bytes:428860 (418.8 KiB)
Interrupt:11 Base address:0x2000
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
virbr0 Link encap:Ethernet HWaddr 52:54:00:4F:C2:A3
inet addr:192.168.122.1 Bcast:192.168.122.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:473 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:49932 (48.7 KiB)
virbr0-nic Link encap:Ethernet HWaddr 52:54:00:4F:C2:A3
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:500
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
由于系统默认的启动网卡是eth0，所以怎么样把eth2更改为eth0成了当务之急。查了很多资料最终终于找到解决方法，方法如下：
修改文件vi /etc/udev/rules.d/70-persistent-net.rules 文件，原来为：
vi /etc/udev/rules.d/70-persistent-net.rules
[root@neal ~]# vi /etc/udev/rules.d/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 0x1af4:0x1000 (virtio-pci)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:57:05:8f", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
# PCI device 0x10ec:0x8139 (8139cp)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:9b:af:6b", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"
# PCI device 0x10ec:0x8139 (8139cp)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:a0:10:38", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"
修改后：
[root@neal ~]# vi /etc/udev/rules.d/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 0x1af4:0x1000 (virtio-pci)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:57:05:8f", ATTR{type}=="1", KERNEL=="eth*", NAME="eth2"
# PCI device 0x10ec:0x8139 (8139cp)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:9b:af:6b", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"
# PCI device 0x10ec:0x8139 (8139cp)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="52:54:00:a0:10:38", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
保存重启后可以看到原来的网络配置又回来了。
转载自：http://hi.baidu.com/li_zhonghui/item/71e4ed52f1f92c15da163596