Personal notes on how to save disk space on my Ubuntu system.

Docker
systemd journal
Snaps
- Removing old versions
  - Retaining fewer old versions
- Removing the cache
Stack (Haskell)
TODO Quicklisp

Docker

Pruning old images and containers

docker image prune
docker container prune

systemd journal

Checking disk usage

$ journalctl --disk-usage
Archived and active journals take up 2.3G in the file system.

Retaining last N days

journalctl --vacuum-time=10d

Snaps

Removing old versions

Snap retains older versions of installed snaps.

$ snap list --all
Name                                  Version                           Rev    Tracking         Publisher          Notes
audacity                              3.1.3                             1032   latest/stable    diddledani✪        disabled
audacity                              3.1.3                             1051   latest/stable    diddledani✪        -
bare                                  1.0                               5      latest/stable    canonical✓         base
chromium                              108.0.5359.124                    2254   latest/stable    canonical✓         disabled
chromium                              109.0.5414.74                     2271   latest/stable    canonical✓         -
…

This list can be used to remove older disabled versions

#!/bin/bash
#Removes old revisions of snaps
#CLOSE ALL SNAPS BEFORE RUNNING THIS
set -eu
LANG=en_US.UTF-8 snap list --all | awk '/disabled/{print $1, $3}' |
    while read snapname revision; do
        snap remove "$snapname" --revision="$revision"
    done

Retaining fewer old versions

sudo snap set system refresh.retain=2

Removing the cache

rm /var/lib/snapd/cache/*

Stack (Haskell)

It is safe to remove .stack/.

TODO Quicklisp

How to remove older versions of systems? Is it safe?