Find Large Files Shell Script Linux

When df shows 95% full, admins search for a find large files shell script — not a one-liner they forget, but a saved report under /var/log that lists the top offenders by size.

What this script does

Scans one or more paths (default /var and /home)
Uses du -ahx on a single filesystem to avoid NFS noise
Sorts human-readable sizes and prints top N lines
Optional minimum size filter (e.g. files over 500M)
Logs timestamped output for trending

Prerequisites

coreutils du and sort
Read access on scanned paths
Run as root for full visibility under /var/lib

Step 1: Save the script

sudo nano /usr/local/bin/find-large-files.sh
sudo chmod +x /usr/local/bin/find-large-files.sh

Step 2: Full script (scroll to read)

find-large-files.sh

#!/usr/bin/env bash
set -euo pipefail

TOP_N="${TOP_N:-20}"
MIN_SIZE="${MIN_SIZE:-}"   # optional: 100M, 1G
LOG="/var/log/find-large-files.log"

log(){ echo "[$(date '+%F %T')] $*" | tee -a "$LOG"; }

scan(){
  local path="$1"
  local n="${2:-$TOP_N}"
  [[ -d "$path" ]] || { log "SKIP missing $path"; return; }
  log "=== Top $n under $path ==="
  if [[ -n "$MIN_SIZE" ]]; then
    find "$path" -xdev -type f -size "+${MIN_SIZE}" -printf '%s %p\n' 2>/dev/null \
      | sort -nr | head -n "$n" \
      | awk '{ printf "%.1fM\t%s\n", $1/1024/1024, $2 }' | tee -a "$LOG"
  else
    du -ahx "$path" 2>/dev/null | sort -hr | head -n "$n" | tee -a "$LOG"
  fi
}

if [[ $# -ge 1 && "$1" != -* ]]; then
  paths=("$@")
  # last arg may be number if numeric
  if [[ "${paths[-1]}" =~ ^[0-9]+$ ]]; then
    TOP_N="${paths[-1]}"
    unset 'paths[-1]'
  fi
else
  paths=("/var" "/home")
fi

for p in "${paths[@]}"; do
  scan "$p" "$TOP_N"
done

Scroll inside the box to read the full script.

Step 3: Configure settings

Complements disk space email alert
See /tmp cleanup script for quick wins
Avoid scanning entire / on busy file servers without -x

Shell script finding large files with du and sort

Step 4: Test manually

sudo ./find-large-files.sh /var 15

sudo ./find-large-files.sh /home 10 500M

Schedule with cron

sudo crontab -e

Add:

0 7 * * 1 /usr/local/bin/find-large-files.sh /var /home 25 >> /var/log/find-large-files.log 2>&1

Find Large Files Shell Script Linux (du, sort, Disk Cleanup)