When I first installed CentOS 6 minimum, I couldn’t figure out how to install the OS without internet connection, but eventually, I figured it out.
The OS that I’m using is CentOS 6.7 minimum, and normally, you’d need Internet connection while installing the OS because you would select URL for the installation method.
To create the bootable USB flash drive, I’ve created a blog post for the instructions. Insert a bootable USB flash drive into the machine and boot into CentOS 6.7.
Install or upgrade an existing system.
Select a language.
Select Hard Drive as the Installation Method.
Select /dev/sda1 as the Select Partition.
Basic Storage Devices.
Type a Hostname.
Select a time zone.
Enter a password.
I chose to use all space on the hard drive.
Add the Hard Drive. Not the USB Disk.
Write changes to disk.
Installation happens without Internet.
Reboot after CentOS installation is complete.
Eject the USB and the computer boots into CentOS 6.7.
Use the CentOS 6.7 as expected!