Introduction

During this setup, we will how we could connect Serial console of Guest CentOS7 over Oracle VirtualBox from the windows7 machine via PuTTY.
HowTo Serial Console CentOS7 From Windows7 Via PuTTY.

Setup

In previous post we saw same setting for CentOS6
We have setup below infra for this post

Host                   -- Windows7
Guest                  -- CentOS7
Virtulization platform -- Oracle VirtualBox
Conneting App          -- PuTTY

For connecting Serial console of CentOS7, we need to change or add some parameters in Linux machine.

First of all, we need to add console parameters in grub.conf file.

GRUB_CMDLINE_LINUX="console=ttyS2,115200"
GRUB_TERMINAL="serial"

Now to get in effect above setting, we need to do mkconfig lke below.

[root@srv7 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Warning: Requested serial terminal but GRUB_SERIAL_COMMAND is unspecified. Default parameters will be used.
Found linux image: /boot/vmlinuz-3.10.0-514.26.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.26.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-514.10.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.10.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-514.2.2.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-514.2.2.el7.x86_64.img
Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-9d036e3fa45f4f44bd08d06ac01543bd
Found initrd image: /boot/initramfs-0-rescue-9d036e3fa45f4f44bd08d06ac01543bd.img
[ 7659.100399] xor: automatically using best checksumming function:
[ 7659.111969]    avx       : 34760.000 MB/sec
[ 7659.132890] raid6: sse2x1   gen()  7894 MB/s
[ 7659.155968] raid6: sse2x2   gen()  9679 MB/s
[ 7659.184979] raid6: sse2x4   gen() 10769 MB/s
[ 7659.198269] raid6: using algorithm sse2x4 gen() (10769 MB/s)
[ 7659.199300] raid6: using ssse3x2 recovery algorithm
[ 7659.223745] Btrfs loaded
[ 7659.229778] fuse init (API version 7.22)
done

Here sometimes one question raises, why we used ttyS2 in Linux and COM3 in windows. Actually, mapping of Linux serial console with Windows COM ports is bit different.
ttyS0 — COM1
ttyS1 — COM2
ttyS2 — COM3
ttyS3 — SOM4

So Above mapping of Linux serial port towards Windows COM ports is the main reason for this confusion.

We also need to edit VM setting in Oracle VirtualBox, virtual machine platform like below

 

 

 

 

 

 

 

 

 

Further, we just need to start connecting Linux machine through PuTTY application. Open PuTTY.

Click on Connection type : Serial
Serial line              : \\.\pipe\COM3
Speed                    : 115200

Click on open. Need to click twice will provide login console.like below