[Tutorial] Install CentOS 7 remotely through VNC

edan

This tuts inspired by the WSI $10 box with free extra 250GB HDD. Some of you perhaps want to setup soft RAID 1 on CentOS 7 and here are the step to achieve that by installing it via VNC.

Boot options between CentOS 6 and CentOS 7 for VNC installatons are different now, you can read it on RedHat.

Download the bootstrap files

yum install wget
cd /boot
wget http://mirror.centos.org/centos/7/os/x86_64/isolinux/vmlinuz -O vmlinuz-7
wget http://mirror.centos.org/centos/7/os/x86_64/isolinux/initrd.img -O initrd-7.img

Creating custom menu entry

The safest thing is we just need to copy menu entry that already exists in /boot/grub2/grub.cfg.

Example existing menu entry:

menuentry 'CentOS Linux, with Linux 3.10.0-123.el7.x86_64' --class centos --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-123.el7.x86_64-advanced-ac9e46e0-6de5-4e6f-baf2-cca39dffe49b' {
    load_video
    set gfxpayload=keep
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint='hd0,msdos1'  ac9e46e0-6de5-4e6f-baf2-cca39dffe49b
    else
      search --no-floppy --fs-uuid --set=root ac9e46e0-6de5-4e6f-baf2-cca39dffe49b
    fi
    linux16 /vmlinuz-3.10.0-123.el7.x86_64 root=UUID=ac9e46e0-6de5-4e6f-baf2-cca39dffe49b ro vconsole.keymap=us crashkernel=auto  vconsole.font=latarcyrheb-sun16 rhgb quiet LANG=en_US.UTF-8
    initrd16 /initramfs-3.10.0-123.el7.x86_64.img
}

And than paste it to /etc/grub.d/40_custom. Modify the menu entry title, the linux16, initrd16..

#!/bin/sh
exec tail -n +3 $0
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.

menuentry 'NetInstall' {
    load_video
    set gfxpayload=keep
    insmod gzio
    insmod part_msdos
    insmod ext2
    set root='hd0,msdos1'
    if [ x$feature_platform_search_hint = xy ]; then
      search --no-floppy --fs-uuid --set=root --hint='hd0,msdos1'  ac9e46e0-6de5-4e6f-baf2-cca39dffe49b
    else
      search --no-floppy --fs-uuid --set=root ac9e46e0-6de5-4e6f-baf2-cca39dffe49b
    fi
    linux16 /vmlinuz-7 inst.vnc inst.vncpassword=12345678 inst.headless ip=ip::gateway:netmask::interface:none nameserver=8.8.8.8 inst.repo=http://mirror.centos.org/centos/7/os/x86_64/ inst.lang=en_US inst.keymap=us
    initrd16 /initrd-7.img
}

Note: replace the ip=ip::gateway:netmask::interface:none with yours. eg:

ip=10.0.0.10::10.0.0.1:255.255.255.0::eth0:none

Make sure to set the right network device.

VNC Password length

MUST between 6-8 char.

Grub configurations

Make sure it only boot our custom menu entry once. In /etc/default/grub, change GRUB_DEFAULT=0 to GRUB_DEFAULT=saved

GRUB_DEFAULT=saved

Save all the configurations.

# rebuilt the grub.cfg

grub2-mkconfig -o /boot/grub2/grub.cfg

# list available menu entry

awk -F\' '$1=="menuentry " {print $2}' /etc/grub2.cfg

# verify the default menu entry

grub2-editenv list

# set the default boot (do this if the default menu entry changed)

grub2-set-default 'CentOS Linux, with Linux 3.10.0-123.el7.x86_64'

# boot our new menu entry for the next reboot. We just need to use the menu entry title.

grub2-reboot NetInstall

Double check your current configurations before rebooting your server.

Wait a moments until the setup finished. You can starting your CentOS 7 remote installatons at YOURIP:1 by using VNC. [Source]