The primary distinction between CentOS-8.1.1911-x86_64-boot.iso and CentOS-8.1.1911-x86_64-dvd1.iso lies in their installation approaches and package management:
- Boot ISO (~630MB): Network-based installer that downloads packages during installation
- DVD ISO (~7GB): Contains complete package repository for offline installation
For developers working with minimal installations:
# Example kickstart file for minimal install using boot.iso
install
url --url="http://mirror.centos.org/centos/8/BaseOS/x86_64/os/"
lang en_US.UTF-8
keyboard us
timezone UTC
rootpw --plaintext temp123
user --name=dev --password=temp123 --groups=wheel
reboot
%packages --nobase
@core
vim-enhanced
curl
wget
git
%end
The boot ISO provides several technical benefits:
- Bandwidth efficiency: Only downloads required packages
- Customization: Easier integration with automated deployment systems
- Flexibility: Can point to local mirrors or custom repositories
The DVD image becomes necessary when:
- Working in air-gapped environments
- Installing on systems without reliable internet
- Needing all available packages immediately
For automated deployments using the boot ISO:
# Sample PXE boot configuration for network install
label centos8-minimal
menu label ^CentOS 8 Minimal
kernel centos8/images/pxeboot/vmlinuz
append initrd=centos8/images/pxeboot/initrd.img \
inst.repo=http://mirror.centos.org/centos/8/BaseOS/x86_64/os/ \
inst.ks=http://kickstart.example.com/minimal.cfg
The boot ISO is particularly valuable for:
- CI/CD pipeline servers
- Container host systems
- Cloud image provisioning
After minimal installation, you can add additional repositories:
# Adding EPEL repository
sudo dnf install epel-release
sudo dnf config-manager --set-enabled powertools
sudo dnf update -y
# Verify available repos
dnf repolist
When working with CentOS 8.1 (1911 release), you'll encounter two primary installation media types:
CentOS-8.1.1911-x86_64-boot.iso (~700MB)
CentOS-8.1.1911-x86_64-dvd1.iso (~7GB)
The boot.iso serves as a network-based installer that provides:
- Minimal environment for system rescue/recovery
- Network installation capability (requires internet connection)
- Basic installer that downloads packages during installation
- No graphical installer by default (text mode only)
Example kickstart file for automated installation:
# Example minimal kickstart configuration
install
url --url="http://mirror.centos.org/centos/8/BaseOS/x86_64/os/"
lang en_US.UTF-8
keyboard us
network --onboot yes --device eth0 --bootproto dhcp
rootpw --plaintext temp_password
firewall --disabled
selinux --disabled
timezone UTC
bootloader --location=mbr
clearpart --all --initlabel
autopart
reboot
%packages --nobase
@core
%end
The dvd1.iso contains:
- Complete offline installation repository
- Graphical and text installation modes
- All base packages (~6,500 RPMs)
- Optional software selection during install
When to use boot.iso:
- Limited bandwidth environments (only downloads needed packages)
- Custom deployments using kickstart/preseed
- Disk space-constrained systems
When to use dvd1.iso:
- Air-gapped or offline installations
- Standard deployments needing GUI installer
- Environments requiring complete package availability
For automated network installations using boot.iso:
# PXE boot configuration example
label centos8-netinstall
menu label ^CentOS 8 Network Install
kernel vmlinuz
append initrd=initrd.img inst.repo=http://mirror.centos.org/centos/8/BaseOS/x86_64/os/ \
inst.ks=http://example.com/kickstart.cfg ip=dhcp
The boot.iso installation will typically take longer as it downloads packages during installation, while dvd1.iso provides better installation performance for complete systems since all packages are locally available.