Hello, On Wed, Mar 31, 2021 at 05:18:34PM +0300, Vitaly Potyarkin wrote: > I'm trying to understand the differences in content and support status of > Debian cloud images found here [1]. It seems to me that Openstack, generic and > genericcloud serve more or less the same purpose - and I'm failing to > understand when to use which. > > Here is what I've gathered so far: > > - Openstack image seems to be the go to one for all use cases, even outside of > Openstack deployments. It also has a more "official" vibe to it, being > grouped into the same section as CD/DVD installer images at this page [2]
That is kind of misleading, it's no more or less official than the others. They are all built according to the policy at: https://wiki.debian.org/Teams/DPL/OfficialImages > - Generic and genericcloud images are listed under "misc and unofficial stuff" > at [2] and provide no stable URLs for the latest build - that suggests these > images are somehow inferior to the Openstack ones. The openstack images provide a stable URL for the latest, but the other images do not. Currently, it's up to the client to choose. It should be easy, they are named by iso date. > - Image size differs drastically between Openstack (535M) and generic (285M), > genericcloud (222M) images. Package list diffs show that openstack adds > some packages like aptitude, python2.7 and firmware-linux-free - but I'm not > sure that those are enough to account for the twice larger size, especially > since generic/genericcloud add some packages too (bridge-utils, curl, > chrony, man-db, manpages, ethtool, etc). Maybe there are some differences in > the build process? The openstack images have a different build process, and the maintainer has made different choices regarding preinstalled software. There's other details regarding the filesystem shrinking- if you care, the list archives contain some discussion. > - The only difference between generic and genericcloud seems to be the kernel: > linux-image-amd64 in generic and linux-image-cloud-amd64 in genericcloud. > For some reason the -cloud kernel is significantly smaller, even though > package description [3] makes no mention of omitted modules (drivers?) Yes, the kernel is the only difference. The cloud kernel omits modules that are unlikely to be useful in a cloud environment. The details are too large for the package description, if you care, diff the configs they ship. > My use case is pretty simple: I'm just looking for a base image to spawn new > virtual machines under libvirt/kvm with cloud-init. I'm inclined to go with > smaller genericcloud images, but I'm a little worried that there are some > hidden footguns I'm not aware of. Wiki page [4] has no mention of generic > cloud images, could someone knowledgeable explain the differences please? genericcloud should work. But if you're worried and don't want to mess with it, generic is a more conservative choice. Hope that helps, Ross
