About images
MAAS provides supported images for stable Ubuntu releases, and for CentOS 7 and CentOS 8.0 releases. Other images can be customised for use with MAAS.
This article will help you learn:
What is a MAAS image?
MAAS images are more than just the operating system kernel. In fact, a usable MAAS image consists of at least four things:
- a bootloader
↗, which boots the computer to the point that an operating system can be loaded. MAAS currently uses one of three types of bootloaders: open firmware, PXE, and UEFI. - a bootable kernel.
- an initial ramdisk.
- a squashfs filesystem.
If you were to look at the squashfs.manifest, you’d see something like this:
adduser 3.118ubuntu5
apparmor 3.0.4-2ubuntu2.1
apport 2.20.11-0ubuntu82.1
apport-symptoms 0.24
apt 2.4.5
apt-utils 2.4.5
base-files 12ubuntu4.1
base-passwd 3.5.52build1
bash 5.1-6ubuntu1
bash-completion 1:2.11-5ubuntu1
bc 1.07.1-3build1
bcache-tools 1.0.8-4ubuntu3
bind9-dnsutils 1:9.18.1-1ubuntu1.1
bind9-host 1:9.18.1-1ubuntu1.1
bind9-libs:amd64 1:9.18.1-1ubuntu1.1
binutils 2.38-3ubuntu1
binutils-common:amd64 2.38-3ubuntu1
binutils-x86-64-linux-gnu 2.38-3ubuntu1
bolt 0.9.2-1
bsdextrautils 2.37.2-4ubuntu3
bsdutils 1:2.37.2-4ubuntu3
btrfs-progs 5.16.2-1
busybox-initramfs 1:1.30.1-7ubuntu3
busybox-static 1:1.30.1-7ubuntu3
byobu 5.133-1
ca-certificates 20211016
cloud-guest-utils 0.32-22-g45fe84a5-0ubuntu1
cloud-init 22.2-0ubuntu1~22.04.3
cloud-initramfs-copymods 0.47ubuntu1
cloud-initramfs-dyn-netconf 0.47ubuntu1
command-not-found 22.04.0
console-setup 1.205ubuntu3
console-setup-linux 1.205ubuntu3
coreutils 8.32-4.1ubuntu1
cpio 2.13+dfsg-7
cron 3.0pl1-137ubuntu3
This snippet gives you a basic idea of the kinds of things that have to be loaded onto a drive in order for the system to function independently.