记一次Centos7 虚拟机突然网卡启动不了
一天突然间网卡起不来了。平常用的好好的，于是上网查了好多解决方案。因为之前的都能用 是正常的 所以在配置文件那块应该不会出现问题。
这里也把配置文件做下笔记
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1）编辑网卡信息
[root@linux-node2~]# cd /etc/sysconfig/network-scripts/ #进入网卡目录
[root@linux-node2network-scripts]# mv ifcfg-eno16777728 ifcfg-eth0 #将默认的网卡名eno16777728改为eth0
[root@linux-node2network-scripts]# cat ifcfg-eth0 #编辑网卡信息
TYPE=Ethernet
BOOTPROTO=static
DEFROUTE=yes
PEERDNS=yes
PEERROUTES=yes
IPV4_FAILURE_FATAL=no
NAME=eth0 #name修改为eth0
ONBOOT=yes
IPADDR=192.168.56.12
NETMASK=255.255.255.0
GATEWAY=192.168.56.2
DNS1=192.168.56.2
2）修改grub
[root@linux-node2~]# cat /etc/sysconfig/grub #编辑内核信息,添加红色字段的
GRUB_TIMEOUT=5
GRUB_DEFAULT=saved
GRUB_DISABLE_SUBMENU=true
GRUB_TERMINAL_OUTPUT="console"
GRUB_CMDLINE_LINUX="crashkernel=autorhgb net.ifnames=0 biosdevname=0 quiet"
GRUB_DISABLE_RECOVERY="true"
[root@linux-node2~]# grub2-mkconfig -o /boot/grub2/grub.cfg #生成启动菜单
Generatinggrub configuration file ...
Foundlinux image: /boot/vmlinuz-3.10.0-229.el7.x86_64
Foundinitrd image: /boot/initramfs-3.10.0-229.el7.x86_64.img
Foundlinux image: /boot/vmlinuz-0-rescue-1100f7e6c97d4afaad2e396403ba7f61
Foundinitrd image: /boot/initramfs-0-rescue-1100f7e6c97d4afaad2e396403ba7f61.img
Done
也可以在开机启动加载安装系统界面设置。
3）验证是否修改成功
[root@linux-node2~]# reboot #必须重启系统生效 [root@linux-node2~]# yum install net-tools #默认centos7不支持ifconfig 需要看装net-tools包 [root@linux-node2~]# ifconfig eth0 #在次查看网卡信息 eth0:flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.56.12 netmask 255.255.255.0 broadcast 192.168.56.255 inet6 fe80::20c:29ff:fe5c:7bb1 prefixlen 64 scopeid 0x20<link> ether 00:0c:29:5c:7b:b1 txqueuelen 1000 (Ethernet) RX packets 152 bytes 14503 (14.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 98 bytes 14402 (14.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
centos7启动网卡服务报错“RTNETLINK answers: File exists”的解决方法
[root@localhost network-scripts]# service NetworkManager stop Starting network (via systemctl): Job for network.service failed because the control process exited with error code. See "systemctl status network.service" and "journalctl -xe" for details. [root@localhost network-scripts]# systemctl status network.service ?.network.service - LSB: Bring up/down networking Loaded: loaded (/etc/rc.d/init.d/network) Active: failed (Result: exit-code) since Mon 2017-03-20 18:41:03 CST; 3min 49s ago Docs: man:systemd-sysv-generator(8) Process: 18880 ExecStart=/etc/rc.d/init.d/network start (code=exited, status=1/FAILURE) Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain network[18880]: RTNETLINK answers: File exists Mar 20 18:41:03 localhost.localdomain systemd[1]: network.service: control process exited, code=exited status=1 Mar 20 18:41:03 localhost.localdomain systemd[1]: Failed to start LSB: Bring up/down networking. Mar 20 18:41:03 localhost.localdomain systemd[1]: Unit network.service entered failed state. Mar 20 18:41:03 localhost.localdomain systemd[1]: network.service failed. 原因分析和解决： 在centos下出现该故障的原因是启动网络的两个服务/etc/init.d/network 和 /etc/init.d/NetworkManager有冲突。 从根本上说是NetworkMaganager（NM）的带来的冲突，停用NetworkManager即可解决。重启即可。 [root@localhost network-scripts]# service NetworkManager stop Redirecting to /bin/systemctl stop NetworkManager.service [root@localhost network-scripts]# systemctl start network.service [root@localhost network-scripts]#
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解决方法：系统自带的NetworkManager这个管理套件影响到网卡的启动，关掉就可以解决
service NetworkManager stop
chkconfig NetworkManager off 开机禁启
然后重启网卡
service network restart
还有一点 先ping通网关
如果网关ping不通
证明虚拟机网络设置有问题
我这里是用net连接
在vnet 连接信息里 应选择Net模式。
哎~~！为了调试 一边排雷一边挖坑 导致浪费了好长时间
