前提条件
VPS当前系统是 CentOS 7(因为要用到 grub2)
可以连接VNC (没有VNC就无法使用安装界面)
VPS架构只支持KVM不支持OVZ
获取网络信息
通过ifconfig获取IP地址和子网掩码信息:
$ ifconfig eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 107.182.30.100(IP地址) netmask 255.255.240.0(子网掩码) broadcast 107.182.31.255 inet6 fe80::a8aa:ff:fe11:f79e prefixlen 64 scopeid 0x20<link> ether aa:aa:00:11:f7:9e txqueuelen 1000 (Ethernet) RX packets 133 bytes 13815 (13.4 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 106 bytes 13375 (13.0 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0 lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10<host> loop txqueuelen 1000 (Local Loopback) RX packets 68 bytes 6264 (6.1 KiB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 68 bytes 6264 (6.1 KiB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
查询网关地址:
$ route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 0.0.0.0 107.182.16.1(网关) 0.0.0.0 UG 100 0 0 eth0 107.182.16.0 0.0.0.0 255.255.240.0 U 100 0 0 eth0
以上我们得到了以下信息:
IP 地址:107.182.30.100
子网掩码:255.255.240.0
网关地址:107.182.16.1
配置启动文件
先安装wget命令
yum -y install wget
然后我们下载需要用于网络启动的内核:
wget -O /boot/initrd.img http://mirror.centos.org/centos/7/os/x86_64/images/pxeboot/initrd.img wget -O /boot/vmlinuz http://mirror.centos.org/centos/7/os/x86_64/images/pxeboot/vmlinuz cp /boot/initrd.img / cp /boot/vmlinuz /
编辑/etc/grub.d/40_custom文件:
$ vi /etc/grub.d/40_custom ... # 在最后增加以下信息: menuentry "Network Install CentOS 7" { set root='(hd0,msdos1)' # linux /vmlinuz repo=http://mirror.centos.org/centos/7/os/x86_64/ ip=IP地址 netmask=子网掩码 gateway=网关地址 nameserver=DNS地址 linux /vmlinuz repo=http://mirror.centos.org/centos/7/os/x86_64/ ip=107.182.30.100 netmask=255.255.240.0 gateway=107.182.16.1 nameserver=1.1.1.1 initrd /initrd.img }
生成grub配置文件:
grub2-mkconfig --output=/boot/grub2/grub.cfg
查看启动项:
$ egrep ^menuentry /etc/grub2.cfg | cut -f 2 -d \' CentOS Linux (3.10.0-957.5.1.el7.x86_64) 7 (Core) CentOS Linux (3.10.0-514.el7.x86_64) 7 (Core) CentOS Linux (0-rescue-16fe1aa10c0b925a57abe21439573c6b) 7 (Core) CentOS Linux (0-rescue-bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb) 7 (Core) menuentry "Network Install CentOS 7" {
因为Network Install CentOS 7位于第一行,因此将默认引导条目设置为4:
grub2-set-default 4
开始安装
当以上操作都完成后,使用reboot重启系统,请在重启之前提前打开VNC,准备进行安装:
reboot
当进入启动画面后,选择Network Install CentOS 7这个菜单:
耐心等待几分钟,就可以看到CentOS 7的网络安装器界面了: