I'd like to install Ubuntu to my little SSD disk, and some core applications like Firefox, Inkscape, and Office, but install all other applications with apt to my big hard disk and my home folder (stuff like games, virtual instruments, documents, Haskell/Dart/Rust/npm frameoworks).
How can I do this easily please at install time, or later?
All the answers on here just seem to be people judgmentally saying "you don't need to do that" from a time before SSDs existed I think.
Surely there's a good way in 2022 to accomplish this common task in Ubuntu.
The automated APT package management system expect a standard system file structure, which you may not change (unless you are prepared to implement your own system, or prefer to compile manually.
Even a little SSD disk of 30 GB (you did not specify the size) should be adequate to host the system files of a Linux system. Your first option therefore is to see whether you have user data on that SSD (home directories, other data elsewhere) that can be moved.
In the unlikely case that you really have a very small SSD, you still can move system directories rather simply to another data volume by replacing the original directories by a symbolic link pointing to the new location.
/optis a very good candidate to move first. It is the directory where manually installed binaries are placed./tmpand/var/tmpwill benefit from moving out to a larger storage volumeIf you use containerized applications, e.g. snap or flatpak, moving out
/var/lib/snapdor/var/lib/flatpakwill gain gigabytes of space.Even specific directories of specific applications can be moved out - the system will find them through the symbolic links.
Needles to say is that these interventions require that the system is not running. Do that, therefore, from a live session.