linux 机器更换硬盘后，network service 异常问题
在实际开发中我们经常会遇到会自己的服务器更换硬盘的情况，这么貌似简单的操作，往往隐藏着其他一系列相关的问题比，比如，我今天就遇到了网卡无法重启的问题。
报出的异常为：Bringing up interface eth0: Device eth0 does not seem to be present,delaying initialization.
仔细分析下，我们更换了硬盘后，有关电脑的所有配置都置换为了新硬盘的信息，我们的系统并没有重装，那么有关网卡的配置信息其实是新硬盘中系统以前的配置，那么跟网络有关的就是MAC地址，这时候我们需要更新为当前电脑的MAC地址。
具体操作：
打开/etc/udev/rules.d/70-persistent-net.rules内容如下面例子所示：
# 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