Before you start installing CentOS, you must download an installation ISO image. Images are available from the CentOS website at https://www.centos.org/download/. The following basic types of media are available:
- DVD ISO
This image contains the installer as well as a set of all packages that can be installed during an interactive installation. This is the recommended download for most users.
- Everything ISO
Contains the installer and all packages available for CentOS. This ISO image can be used to install the system with extra packages (using a Kickstart file and specifying extra packages in the
%packagessection); it can also be used to set up a local mirror for downloading packages. Note that this image is very large and requires an at least 16 GB flash drive or other storage.
- Minimal ISO
Contains the installer and a minimal set of packages which can be used to install a very basic CentOS system. You can then use Yum to download additional packages from update repositories.
The images listed on the page linked above are for the AMD64/Intel 64 (
x86_64) architecture, which is the CentOS basic distribution. Images for additional architectures such as 64-bit ARM (
aarch64) or IBM Power Systems (
ppc64), as well as cloud and container images, network install media (only the installer, requires a local package mirror) and live images, are available for download from the CentOS Wiki download page.
Optionally, you can use a checksum utility such as sha256sum to verify the integrity of the image file after the download finishes. All downloads are provided with their checksums for reference:
$ sha256sum CentOS-server-7.6.1810-x86_64-dvd.iso
After you have downloaded an ISO image file from the Customer Portal, you can:
Burn it to a CD or DVD as described in Making an Installation CD or DVD.
Use it to create a bootable USB drive; see Making Installation USB Media.
Place it on a server to prepare for a network installation. For specific directions, see Installation Source on a Network.
Place it on a hard drive to use the drive as an installation source. For specific instructions, see Installation Source on a Hard Drive.
Use it to prepare a Preboot Execution Environment (PXE) server, which allows you to boot the installation system over a network. See Preparing for a Network Installation for instructions.