Create CentOS Bootable USB

Linux Tutorials - Herong's Tutorial Examples

∟Create CentOS Bootable USB

This section provides a tutorial example on how to download the full CentOS ISO image file and create a bootable USB drive on a macOS computer.

CentOS 8 is the latest release of the CentOS system, which is the open source version of RHEL (Red Hat Enterprise Linux). If you want to try it, you can follow what I did as described below to down the CentOS 8.1 ISO image file and create a bootable USB drive.

1. Go to CentOS download Website at https://wiki.centos.org/Download. I see a list of CentOS 8, 7, and 6 download options.

2. Click "mirrors" button next to "CentOS 8.1 (1911)" I see a list of download mirror sites.

3. Select a mirror site near you, like http://centos.les.net/. I see two ISO image files: CentOS-8.1.1911-x86_64-boot.iso, and CentOS-8.1.1911-x86_64-dvd1.iso. They are for computers with an x86_64 CPU architecture.

*-boot.iso is much smaller and contains only the bootable CentOS 8 kernel. When installing CentOS 8 with *-boot.iso, additional system and application packages needed to be downloaded on the fly.
*-dvd1.iso is much larger and contains all system packages and basic application packages. You can install CentOS 8 with *-dvd1.iso without download anything from the Internet.

4. Click "CentOS-8.1.1911-x86_64-dvd1.iso" and save it to my macOS computer. I select CentOS-8.1.1911-x86_64-dvd1.iso, because it matches the CPU architecture x86_64 of the Lenovo computer I want to install CentOS on. You can select ISO files for other architectures by going to the parent directory on the mirror site.

5. Wait until the download is completed, which may take some time.

6. Copy "CentOS-8.1.1911-x86_64-dvd1.iso" to a USB drive using the "dd" command on my macOS computer. You can also do this by using "Etcher" or "Rufus" ISO tools, which is much safer than the "dd" command.

(list file systems on storage devices)
macOS$ df
/dev/disk1           29% 1024263 4293943016    0%   /
/dev/disk2s1          3%       0          0  100%   /Volumes/NO NAME

(copy ISO file to the USB drive, /dev/disk2, not the file system)
(large block size of 64k is more efficient and take less time)
sudo dd if=CentOS-8.1.1911-x86_64-dvd1.iso of=/dev/disk2 bs=64k