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🧹 Linux System Cleaning Guide

Keep your Linux system lean, fast, and clutter-free — covering package cache, user cache, logs, orphaned packages, temp files, and more. Tested on openSUSE, Arch Linux, and Debian/Ubuntu.

📋 Table of Contents

  1. The Problem
  2. Quick Wins — One-Liners
  3. Method 1 – Package Cache Cleaning
  4. Method 2 – User Cache (~/.cache)
  5. Method 3 – System Logs (journald)
  6. Method 4 – Orphaned Packages
  7. Method 5 – Temp Files & /tmp
  8. Method 6 – Flatpak & Snap Cleanup
  9. Method 7 – Old Kernels
  10. Method 8 – Find & Kill Large Files
  11. Method 9 – Zsh / Shell History Trim
  12. Method 10 – Automated All-in-One Script
  13. Aliases for Daily Use
  14. What NOT to Delete
  15. Troubleshooting

The Problem

Over time, Linux accumulates:

  • Package manager caches — downloaded .rpm / .deb / .pkg.tar.zst files that served their purpose and are now dead weight
  • Application caches — browser data, thumbnail indexes, font caches, app-specific junk
  • System logs — journald will happily grow to gigabytes if unchecked
  • Orphaned packages — libraries installed as dependencies for software you long since removed
  • Old kernels — each kernel update leaves the previous one on disk "just in case"
  • Temp files — /tmp and /var/tmp accumulate crash dumps, editor backups, partial downloads

None of this is dangerous. But it wastes disk space, slows down package operations, and makes your system harder to audit.

Quick Wins — One-Liners

Run these right now for an immediate cleanup. Details and safe versions follow in each method section.

# openSUSE — clean zypper cache
sudo zypper clean --all

# Arch — clean pacman cache (keep last 2 versions)
sudo paccache -rk2

# Debian/Ubuntu — clean apt cache
sudo apt clean && sudo apt autoremove --purge

# All distros — clear user cache (check size first!)
du -sh ~/.cache && rm -rf ~/.cache/*

# All distros — vacuum journal logs older than 2 weeks
sudo journalctl --vacuum-time=2weeks

# All distros — remove leftover temp files
sudo find /tmp /var/tmp -type f -atime +7 -delete

Method 1 – Package Cache Cleaning

Package managers cache downloaded packages locally. After installation, these files have no ongoing purpose.

openSUSE (zypper)

# See how much the cache is using
sudo du -sh /var/cache/zypp/packages/

# Clean all cached packages
sudo zypper clean --all

# Clean only metadata (keeps packages, removes repo metadata)
sudo zypper clean --metadata

# Aggressive: remove everything including repo data
sudo zypper clean -a

openSUSE note: Zypper's cache lives at /var/cache/zypp/. It can easily reach 2–5 GB after several system updates.

Arch Linux (pacman)

# Install paccache (from pacman-contrib)
sudo pacman -S pacman-contrib

# Check cache size
du -sh /var/cache/pacman/pkg/

# Keep last 2 versions of each package (safe default)
sudo paccache -rk2

# Keep only the currently installed version
sudo paccache -rk1

# Remove ALL cached packages (nuclear option)
sudo pacman -Scc

# Auto-clean on every pacman transaction (hook)
sudo systemctl enable paccache.timer

Debian / Ubuntu (apt)

# Check cache size
du -sh /var/cache/apt/archives/

# Remove downloaded .deb files
sudo apt clean

# Remove partial downloads only
sudo apt autoclean

# Remove unused dependencies
sudo apt autoremove --purge

# All at once
sudo apt clean && sudo apt autoclean && sudo apt autoremove --purge

Method 2 – User Cache (~/.cache)

~/.cache is populated by browsers, thumbnails, fonts, LSP servers, pip, npm, and virtually every desktop app. It is safe to delete entirely — apps recreate it on next launch.

Check what's eating space

# Total size
du -sh ~/.cache

# Top 10 largest subdirectories
du -sh ~/.cache/*/ 2>/dev/null | sort -rh | head -10

Selective cleaning (recommended)

# Browser caches (Firefox / Chromium)
rm -rf ~/.cache/mozilla/firefox/*/cache2/
rm -rf ~/.cache/chromium/Default/Cache/

# Thumbnail cache (regenerated automatically)
rm -rf ~/.cache/thumbnails/

# Fontconfig cache
rm -rf ~/.cache/fontconfig/

# pip cache
rm -rf ~/.cache/pip/

# npm cache
npm cache clean --force

# Rust / cargo build cache
rm -rf ~/.cache/sccache/

Nuclear option (clears everything)

# Preview first
du -sh ~/.cache

# Then delete
rm -rf ~/.cache/*

echo "Cache cleared — apps will rebuild on next launch"

Method 3 – System Logs (journald)

systemd-journald stores logs in /var/log/journal/. Without limits, it can silently grow to gigabytes.

Check current log size

journalctl --disk-usage

Vacuum by time (recommended)

# Keep only logs from the last 2 weeks
sudo journalctl --vacuum-time=2weeks

# Keep only logs from the last 3 days
sudo journalctl --vacuum-time=3days

Vacuum by size

# Trim logs down to 200MB total
sudo journalctl --vacuum-size=200M

# Trim to 100MB
sudo journalctl --vacuum-size=100M

Set a permanent size cap

Edit /etc/systemd/journald.conf:

sudo nano /etc/systemd/journald.conf

Add or uncomment:

[Journal]
SystemMaxUse=200M
SystemKeepFree=500M
MaxRetentionSec=2weeks

Apply the change:

sudo systemctl restart systemd-journald

⚠️ Without SystemMaxUse, journald defaults to 10% of your filesystem. On a 1TB drive that's 100GB of potential logs.

Method 4 – Orphaned Packages

These are packages installed as dependencies for software you've since removed. They linger silently.

openSUSE

# List orphaned packages (installed but not required by anything)
zypper packages --orphaned

# Remove them (review the list before confirming)
sudo zypper remove --clean-deps $(zypper packages --orphaned | awk -F'|' 'NR>4 {print $3}' | tr -d ' ')

Arch Linux

# List orphans (packages not required by any other package)
pacman -Qtdq

# Remove orphans
sudo pacman -Rns $(pacman -Qtdq)

# If no orphans exist, pacman will report an error — that's fine

Debian / Ubuntu

# List auto-installed packages no longer needed
apt-mark showmanual | head -20   # show manually installed
sudo apt autoremove --purge      # remove unneeded auto-deps

# For deeper auditing
sudo apt install deborphan
deborphan                        # list orphaned libraries
sudo deborphan | xargs sudo apt remove --purge

Method 5 – Temp Files & /tmp

/tmp is cleared on reboot on most systems, but /var/tmp persists across reboots by design.

Check sizes

du -sh /tmp /var/tmp

Remove files not accessed in 7+ days

# Dry run first — see what would be deleted
find /tmp /var/tmp -type f -atime +7

# Then delete
sudo find /tmp /var/tmp -type f -atime +7 -delete

Force-clear /tmp right now

# Safe: only delete files (not directories or symlinks)
sudo find /tmp -maxdepth 1 -mindepth 1 -type f -delete

# Nuclear: wipe /tmp entirely (closes open temp files — reboot after)
sudo rm -rf /tmp/*

Configure systemd-tmpfiles (permanent policy)

# See current rules
cat /usr/lib/tmpfiles.d/tmp.conf

# View or override with a local rule
sudo nano /etc/tmpfiles.d/tmp.conf

Example rule — clear files in /tmp older than 1 day on boot:

d /tmp 1777 root root 1d

Method 6 – Flatpak & Snap Cleanup

Flatpak and Snap store old runtimes and app versions indefinitely.

Flatpak

# List installed apps and their sizes
flatpak list --app --columns=application,size

# Remove unused runtimes (biggest space saver)
flatpak uninstall --unused

# Remove a specific app
flatpak uninstall com.example.App

# Full cleanup
flatpak uninstall --unused && flatpak repair

Snap

# List all snaps and versions
snap list --all

# Snaps keep old revisions on disk — remove them
snap list --all | awk '/disabled/{print $1, $3}' | \
  while read snapname revision; do
    sudo snap remove "$snapname" --revision="$revision"
  done

openSUSE note: Snap is not officially supported on openSUSE Tumbleweed. Flatpak is available via sudo zypper install flatpak.

Method 7 – Old Kernels

Each kernel update keeps the previous version as a safety net. After confirming the new kernel works, the old ones are just dead weight.

Check installed kernels

# All distros
uname -r                          # currently running kernel

# openSUSE
rpm -qa | grep kernel-default

# Arch
pacman -Q linux linux-lts         # or whatever kernel you use

# Debian/Ubuntu
dpkg --list | grep linux-image

openSUSE — remove old kernels

# zypper handles this automatically with zypper dup
# To manually keep only the latest:
sudo zypper remove $(rpm -qa | grep kernel-default | sort -V | head -n -1)

Arch Linux

# Arch only keeps one kernel unless you explicitly install extras (linux-lts, etc.)
# List all kernel packages
pacman -Q | grep linux

# Remove a specific old one
sudo pacman -Rns linux-lts   # only if you don't need it

Debian / Ubuntu

# List old kernels
dpkg --list | grep linux-image | grep -v $(uname -r)

# Remove old kernels automatically
sudo apt autoremove --purge

# Manual removal
sudo apt remove --purge linux-image-5.15.0-76-generic
sudo update-grub

⚠️ Never remove your currently running kernel. Always confirm with uname -r first and keep at least one fallback.

Method 8 – Find & Kill Large Files

Sometimes disk space disappears mysteriously. This is how you hunt it down.

Find the biggest directories

# Top 10 largest directories from root (skip pseudo-filesystems)
sudo du -h --exclude=/proc --exclude=/sys --exclude=/dev \
  -d 2 / 2>/dev/null | sort -rh | head -20

# Top 10 in your home directory
du -sh ~/* 2>/dev/null | sort -rh | head -10

# Drill into a specific directory
du -sh ~/.local/share/*/ | sort -rh | head -10

Find large files directly

# Files over 100MB anywhere on disk
sudo find / -xdev -size +100M -type f 2>/dev/null | sort

# Files over 1GB
sudo find / -xdev -size +1G -type f 2>/dev/null

# Large files in your home directory only
find ~ -size +50M -type f 2>/dev/null | sort -k5 -rh

Common culprits

# VM disk images (VirtualBox / QEMU)
find ~ -name "*.vdi" -o -name "*.vmdk" -o -name "*.qcow2" 2>/dev/null

# Core dumps
find / -name "core" -type f 2>/dev/null
sudo find /var/lib/systemd/coredump/ -type f -delete

# Old Docker images and volumes
docker system df
docker system prune -a --volumes   # nuclear — removes all unused docker data

# Steam games
du -sh ~/.local/share/Steam/steamapps/common/*/ 2>/dev/null | sort -rh | head -10

Method 9 – Zsh / Shell History Trim

Shell history files grow unbounded unless you set limits.

Check current history file size

du -sh ~/.zsh_history ~/.bash_history 2>/dev/null
wc -l ~/.zsh_history

Set history limits in ~/.zshrc

# Add or update these lines in ~/.zshrc
HISTSIZE=5000           # lines kept in memory per session
SAVEHIST=10000          # lines saved to ~/.zsh_history
HISTFILE=~/.zsh_history

# Deduplicate history (don't save repeated commands)
setopt HIST_IGNORE_DUPS
setopt HIST_IGNORE_ALL_DUPS
setopt HIST_SAVE_NO_DUPS

# Don't save commands starting with a space
setopt HIST_IGNORE_SPACE

Apply:

source ~/.zshrc

Manually trim history right now

# Back up first
cp ~/.zsh_history ~/.zsh_history.bak

# Keep only the last 5000 lines
tail -5000 ~/.zsh_history > /tmp/zsh_history_trim && mv /tmp/zsh_history_trim ~/.zsh_history

Method 10 – Automated All-in-One Script

A single script that handles all the common cleaning tasks, shows space saved, and logs what was done.

#!/usr/bin/env bash
# ============================================================
# system-clean.sh
# Cleans package cache, user cache, logs, temp files, orphans.
# Usage: ./system-clean.sh [--dry-run]
# ============================================================

set -euo pipefail

DRY_RUN=false
[[ "${1:-}" == "--dry-run" ]] && DRY_RUN=true

LOG_FILE="/tmp/system-clean-$(date +%Y%m%d-%H%M%S).log"
FREED=0

log() { echo "$1" | tee -a "$LOG_FILE"; }
hr()  { log "──────────────────────────────────────────"; }

dir_size_kb() { du -sk "$1" 2>/dev/null | awk '{print $1}'; }

run() {
    if $DRY_RUN; then
        log "  [DRY-RUN] $*"
    else
        eval "$@" >> "$LOG_FILE" 2>&1 || true
    fi
}

hr
log "🧹 system-clean.sh — $(date)"
log "   Mode: $( $DRY_RUN && echo DRY RUN || echo LIVE )"
hr

# ── 1. Package cache ──────────────────────────────────────
log ""
log "▶ Package cache"

if command -v zypper &>/dev/null; then
    before=$(dir_size_kb /var/cache/zypp/packages)
    run "sudo zypper clean --all"
    after=$(dir_size_kb /var/cache/zypp/packages)
    freed_here=$(( before - after ))
    log "  zypper: freed ~${freed_here} KB"
    FREED=$(( FREED + freed_here ))

elif command -v paccache &>/dev/null; then
    before=$(dir_size_kb /var/cache/pacman/pkg)
    run "sudo paccache -rk2 -q"
    after=$(dir_size_kb /var/cache/pacman/pkg)
    freed_here=$(( before - after ))
    log "  paccache: freed ~${freed_here} KB"
    FREED=$(( FREED + freed_here ))

elif command -v apt &>/dev/null; then
    before=$(dir_size_kb /var/cache/apt/archives)
    run "sudo apt clean"
    run "sudo apt autoremove --purge -y"
    after=$(dir_size_kb /var/cache/apt/archives)
    freed_here=$(( before - after ))
    log "  apt: freed ~${freed_here} KB"
    FREED=$(( FREED + freed_here ))
fi

# ── 2. User cache ─────────────────────────────────────────
log ""
log "▶ User cache (~/.cache)"
before=$(dir_size_kb ~/.cache)
run "rm -rf ~/.cache/*"
after=$(dir_size_kb ~/.cache)
freed_here=$(( before - after ))
log "  ~/.cache: freed ~${freed_here} KB"
FREED=$(( FREED + freed_here ))

# ── 3. Journal logs ───────────────────────────────────────
log ""
log "▶ Journal logs (keeping last 2 weeks)"
run "sudo journalctl --vacuum-time=2weeks"

# ── 4. Temp files ─────────────────────────────────────────
log ""
log "▶ Temp files older than 7 days"
before_tmp=$(dir_size_kb /tmp)
before_var=$(dir_size_kb /var/tmp)
run "sudo find /tmp /var/tmp -type f -atime +7 -delete"
after_tmp=$(dir_size_kb /tmp)
after_var=$(dir_size_kb /var/tmp)
freed_here=$(( (before_tmp + before_var) - (after_tmp + after_var) ))
log "  /tmp + /var/tmp: freed ~${freed_here} KB"
FREED=$(( FREED + freed_here ))

# ── 5. Flatpak unused runtimes ────────────────────────────
if command -v flatpak &>/dev/null; then
    log ""
    log "▶ Flatpak unused runtimes"
    run "flatpak uninstall --unused -y"
fi

# ── 6. Thumbnail cache ────────────────────────────────────
log ""
log "▶ Thumbnail cache"
before=$(dir_size_kb ~/.cache/thumbnails 2>/dev/null || echo 0)
run "rm -rf ~/.cache/thumbnails/*"
log "  thumbnails: freed ~${before} KB"
FREED=$(( FREED + before ))

# ── Summary ───────────────────────────────────────────────
hr
log ""
freed_mb=$(awk "BEGIN {printf \"%.1f\", $FREED/1024}")
log "✅ Done! Estimated space freed: ~${freed_mb} MB"
log "   Log saved to: $LOG_FILE"
log ""
hr
chmod +x system-clean.sh

# Dry run first — see what would happen
./system-clean.sh --dry-run

# Live run
./system-clean.sh

Aliases for Daily Use

Add these to ~/.zshrc for fast, one-command cleaning.

# ── Cleaning aliases ─────────────────────────────────────

# Show cache size, clean it, confirm it's gone
alias clean-cache='echo "Before: $(du -sh ~/.cache)" && rm -rf ~/.cache/* && echo "After:  $(du -sh ~/.cache)"'

# Clean package cache (auto-detects distro)
alias clean-pkg='
  if command -v zypper &>/dev/null; then sudo zypper clean --all
  elif command -v paccache &>/dev/null; then sudo paccache -rk2
  elif command -v apt &>/dev/null; then sudo apt clean && sudo apt autoremove --purge
  fi
'

# Vacuum journal logs
alias clean-logs='sudo journalctl --vacuum-time=2weeks && journalctl --disk-usage'

# Show disk usage summary
alias diskcheck='df -h / && echo "" && du -sh ~/* 2>/dev/null | sort -rh | head -10'

# Show top 10 largest files in current directory
alias bigfiles='du -sh ./*/ 2>/dev/null | sort -rh | head -10'

# Full system clean (runs the script above)
alias clean-system='~/scripts/system-clean.sh'

Reload:

source ~/.zshrc

What NOT to Delete

Some things look like junk but are critical. Leave these alone.

Path Why it matters
~/.config/ App settings and configurations — deleting breaks things
~/.local/share/ App data, installed fonts, Flatpak apps, Steam games
/var/log/ (all of it) Some logs are not managed by journald — check before deleting
/var/lib/pacman/ Arch package database — deleting corrupts pacman
/var/lib/rpm/ openSUSE RPM database — same risk
/boot/ Kernels and bootloader — only touch old kernels with care
/etc/ System configuration — never blindly delete here
~/.gnupg/ GPG keys — deleting means you lose signed git commits, encrypted files
~/.ssh/ SSH keys — deleting locks you out of servers

Troubleshooting

zypper clean reports nothing to clean

# Cache may already be empty, or the path changed
sudo du -sh /var/cache/zypp/
ls /var/cache/zypp/packages/

paccache: command not found

# paccache is in pacman-contrib, not installed by default
sudo pacman -S pacman-contrib

Cleaning ~/.cache broke an app

Most apps recreate their cache automatically. If an app misbehaves after a cache clear:

# Just relaunch the app — it will rebuild its cache
# If it asks to re-login, that's normal (session tokens live in cache sometimes)

# For browsers: re-login to sites, re-accept permissions
# For LSP servers (nvim, vscode): cache rebuilds on first file open

journalctl --vacuum-time has no effect

# Check if persistent logging is even enabled
ls /var/log/journal/

# If empty, logs are only in memory. Enable persistent logging:
sudo mkdir -p /var/log/journal
sudo systemd-tmpfiles --create --prefix /var/log/journal
sudo systemctl restart systemd-journald

apt autoremove wants to remove something important

# Mark it as manually installed so apt stops trying to remove it
sudo apt-mark manual <package-name>

# Then rerun autoremove safely
sudo apt autoremove --purge

Quick Reference Card

TASK                              TOOL           COMMAND
──────────────────────────────────────────────────────────────────────
Clean package cache               zypper         sudo zypper clean --all
Clean package cache               pacman         sudo paccache -rk2
Clean package cache               apt            sudo apt clean && sudo apt autoremove --purge
Clear user cache                  rm             rm -rf ~/.cache/*
Vacuum journal logs (2 weeks)     journalctl     sudo journalctl --vacuum-time=2weeks
Vacuum journal logs (200MB cap)   journalctl     sudo journalctl --vacuum-size=200M
Remove orphans                    pacman         sudo pacman -Rns $(pacman -Qtdq)
Remove orphans                    apt            sudo apt autoremove --purge
Remove Flatpak unused runtimes    flatpak        flatpak uninstall --unused
Find largest dirs in home         du             du -sh ~/*/ | sort -rh | head -10
Find files over 100MB             find           sudo find / -xdev -size +100M -type f
Clear old temp files              find           sudo find /tmp /var/tmp -atime +7 -delete
Check journal disk usage          journalctl     journalctl --disk-usage
Show disk usage                   df             df -h /

Last updated: 2025 | Tested on openSUSE Tumbleweed, Arch Linux, Ubuntu 24.04