Linux device eth0 does not seem to present

vm虚拟机克隆后，启动系统后不能上网，通过ifconfig查看网卡没启动，所以service network restart一下，出现就是：device eth0 does not seem to be present, delaying initialization，然后想到是不是ifcfg-eth0的配置文件里保存了以前的MAC地址，就把这一行删除掉在重启网卡，

1.因为是克隆的所以会把网卡也克隆过来，需要修改mac地址，方法如下

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 0x1022:0x2000 (pcnet32)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:8f:89:9
7", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
# PCI device 0x1022:0x2000 (pcnet32)
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:0c:29:50:bd:1
7", ATTR{type}=="1", KERNEL=="eth*", NAME="eth1"

记录下，eth1网卡的mac地址00:0c:29:50:bd:17

接下来，打开/etc/sysconfig/network-scripts/ifcfg-eth0

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

将 DEVICE=”eth0” 改成 DEVICE=”eth1” ,

将 HWADDR=”00:0c:29:8f:89:97” 改成上面的mac地址 HWADDR=”00:0c:29:50:bd:17”

最后，重启网络

# service network restart
或者

# /etc/init.d/network restart

2.也可以删除后直接重启。因为这个文件绑定了网卡和mac地址，所以换了网卡以后MAC地址变了，所以不能正常启动，也可以直接编辑这个配置文件把里面的网卡和mac地址修改乘对应的，不过这样多麻烦，直接删除重启，它会自动生成个。