/etc/ resolv.conf文件中的 namesever 在重启RedHat5或重启service network restart 后丢失，我按文件的说明到/etc/sysconfig/network-scripts/ ifcfg-eth0 添加DNS后解决。但是我不知道到底是什么在重启的时候重写了/etc/ resolv.conf文件。

/etc/ resolv.conf文件如下：

nameserver 59.51.78.210 nameserver 59.51.78.211 nameserver 192.168.0.1 search domain domain domain # Generated by NetworkManager

# No nameservers found; try putting DNS servers into your # ifcfg files in /etc/sysconfig/network-scripts like so:

# DNS1=xxx.xxx.xxx.xxx # DNS2=xxx.xxx.xxx.xxx # DOMAIN=lab.foo.com bar.foo.com =============================================== /etc/sysconfig/network-scripts/ ifcfg-eth0 的内容：

# Intel Corporation 82540EM Gigabit Ethernet Controller DEVICE=eth0 BOOTPROTO=none ONBOOT=yes HWADDR=08:00:27:cc:64:86 NETMASK=255.255.255.0 IPADDR=192.168.0.155 GATEWAY=192.168.0.1 TYPE=Ethernet USERCTL=no IPV6INIT=no PEERDNS=no

#我在这添加了DNS后，/etc/ resolv.conf文件内容保存下来了 DNS1=202.96.128.86 DNS2=202.96.128.166 DNS3=8.8.8.8