CentOS 6 is in archived state, but may still be used for education purposes.

This post guides you through the installation process: (1) Download ISO file (2) Enable Network (3) Set up package manager mirror URL.

Download ISO File

Visit CentOS Vault Mirror and download CentOS-6.10-x86_64-minimal.iso.

Set up a virtual machine with VirtualBox. Make sure to choose a larger dynamic disk size (such as 100 GB). If your disk size is too small, you may need to change it afterwards, and the process is non-trivial.

Enable Network

ping google.com

should report an error: ping: unknown host google.com

ip a

should show something like eth0 in the output.

vi /etc/sysconfig/network-scripts/ifcfg-eth0

and change ONBOOT=no to ONBOOT=yes, and use reboot to reboot.

Set up package manager mirror URL

vi /etc/yum.repos.d/CentOS-Base.repo

and modify with vi commands:


These commands comment out mirrorlist lines and uncomment baseurl lines and replace http://mirror.centos.org/centos/$releasever/[SECTION]/$basearch/ to http://vault.centos.org/centos/$releasever/[SECTION]/$basearch/.

perform the modifcations on all 5 sections: [base], [updates], [extras], [centosplus], [contrib].

yum update

Install tmux

See this post to install from source. I have trouble installing it through yum.

VirtualBox Guest Additions

If the OS is installed in VirtualBox, you can insert Guest Additions CDROM and install with:

sudo mkdir -p /mnt/cdrom
sudo mount -t auto /dev/cdrom1 /mnt/cdrom
cd /mnt/cdrom
sudo sh ./VBoxLinuxAdditions.run --nox11
lsmod | grep vboxguest

See this post for more details.