linux_system_tuning/demo-tmpfs-scan.sh

#!/bin/bash
# Demonstration script showing tmpfs/overlay detection and setup
# This script shows what would happen on a fresh system

set -euo pipefail

# Colors
RED='\033[0;31m'
GREEN='\033[0;32m'
YELLOW='\033[1;33m'
BLUE='\033[0;34m'
NC='\033[0m'

log() {
    echo -e "${BLUE}[INFO]${NC} $1"
}

success() {
    echo -e "${GREEN}[SUCCESS]${NC} $1"
}

warn() {
    echo -e "${YELLOW}[SCAN]${NC} $1"
}

error() {
    echo -e "${RED}[WOULD DO]${NC} $1"
}

echo "🔍 tmpfs/Overlay Detection and Setup Demonstration"
echo "=================================================="
echo ""

simulate_fresh_system_scan() {
    log "Simulating scan on a fresh system without existing tmpfs optimizations..."
    echo ""
    
    local ram_gb=$(free -g | awk '/^Mem:/{print $2}')
    log "Detected system: ${ram_gb}GB RAM, $(nproc) CPU cores"
    echo ""
    
    warn "Scanning for folders/software that would benefit from tmpfs..."
    echo ""
    
    # Browser detection
    warn "🌐 Browser Analysis:"
    
    # Firefox
    find /home -path "*/.mozilla/firefox/*/prefs.js" 2>/dev/null | head -3 | while read prefs_file; do
        profile_dir=$(dirname "$prefs_file")
        profile_name=$(basename "$profile_dir")
        cache_dir="$profile_dir/storage"
        if [[ -d "$cache_dir" ]]; then
            size=$(du -sh "$cache_dir" 2>/dev/null | cut -f1)
            warn "  Found Firefox profile: $profile_name ($size cache)"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/browser/firefox-$profile_name"
            error "  → Would symlink: $cache_dir → tmpfs"
        fi
    done
    
    # Chrome/Chromium
    find /home -path "*/.config/google-chrome/*/Preferences" -o -path "*/.config/chromium/*/Preferences" 2>/dev/null | head -3 | while read prefs_file; do
        profile_dir=$(dirname "$prefs_file")
        browser_type=$(echo "$profile_dir" | grep -o -E "(google-chrome|chromium)" || echo "chrome")
        profile_name=$(basename "$profile_dir")
        cache_dir="$profile_dir/storage"
        if [[ -d "$cache_dir" ]]; then
            size=$(du -sh "$cache_dir" 2>/dev/null | cut -f1)
            warn "  Found $browser_type profile: $profile_name ($size cache)"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/browser/$browser_type-$profile_name"
            error "  → Would symlink: $cache_dir → tmpfs"
        fi
    done
    
    # Brave (if present)
    find /home -path "*/.config/BraveSoftware/*/Preferences" 2>/dev/null | head -3 | while read prefs_file; do
        profile_dir=$(dirname "$prefs_file")
        profile_name=$(basename "$profile_dir")
        cache_dir="$profile_dir/storage"
        if [[ -d "$cache_dir" ]]; then
            size=$(du -sh "$cache_dir" 2>/dev/null | cut -f1)
            warn "  Found Brave profile: $profile_name ($size cache)"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/browser/brave-$profile_name"
            error "  → Would symlink: $cache_dir → tmpfs"
        fi
    done
    
    echo ""
    warn "💻 Development Tools Analysis:"
    
    # VS Code
    find /home -path "*/.config/Code/CachedData" 2>/dev/null | while read vscode_cache; do
        if [[ -d "$vscode_cache" ]]; then
            size=$(du -sh "$vscode_cache" 2>/dev/null | cut -f1)
            warn "  Found VS Code cache: $size"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/ide/vscode-cache"
            error "  → Would symlink: $vscode_cache → tmpfs"
        fi
    done
    
    # JetBrains IDEs
    find /home -path "*/.config/JetBrains/*/system" 2>/dev/null | while read jetbrains_cache; do
        if [[ -d "$jetbrains_cache" ]]; then
            ide_name=$(echo "$jetbrains_cache" | grep -o "JetBrains/[^/]*" | cut -d/ -f2)
            size=$(du -sh "$jetbrains_cache" 2>/dev/null | cut -f1)
            warn "  Found $ide_name cache: $size"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/ide/$ide_name"
            error "  → Would symlink: $jetbrains_cache → tmpfs"
        fi
    done
    
    # Node.js projects
    if command -v node >/dev/null 2>&1; then
        warn "  Node.js detected - scanning for large node_modules directories"
        find /home -name "node_modules" -type d 2>/dev/null | head -5 | while read node_dir; do
            if [[ -d "$node_dir" ]]; then
                size=$(du -sh "$node_dir" 2>/dev/null | cut -f1)
                project_path=$(dirname "$node_dir")
                warn "    Found: $project_path ($size)"
                error "    → Could create overlay mount for faster access"
            fi
        done
    fi
    
    echo ""
    warn "📦 System Cache Analysis:"
    
    # Package manager caches
    if [[ -d /var/cache/apt ]]; then
        size=$(du -sh /var/cache/apt 2>/dev/null | cut -f1)
        warn "  Found APT package cache: $size"
        error "  → Would create tmpfs mount: /tmp/tmpfs-cache/packages (2G)"
        error "  → Would bind mount: /var/cache/apt → tmpfs"
    fi
    
    if [[ -d /var/cache/pacman ]]; then
        size=$(du -sh /var/cache/pacman 2>/dev/null | cut -f1)
        warn "  Found Pacman package cache: $size"
        error "  → Would create tmpfs mount: /tmp/tmpfs-cache/packages (2G)"
        error "  → Would bind mount: /var/cache/pacman → tmpfs"
    fi
    
    # User thumbnail caches
    find /home -path "*/.cache/thumbnails" 2>/dev/null | while read thumb_dir; do
        if [[ -d "$thumb_dir" ]]; then
            size=$(du -sh "$thumb_dir" 2>/dev/null | cut -f1)
            user=$(echo "$thumb_dir" | cut -d'/' -f3)
            warn "  Found thumbnail cache for $user: $size"
            error "  → Would create tmpfs mount: /tmp/tmpfs-cache/thumbnails/$user"
            error "  → Would symlink: $thumb_dir → tmpfs"
        fi
    done
    
    echo ""
    calculate_optimization_summary "$ram_gb"
}

calculate_optimization_summary() {
    local ram_gb=$1
    
    success "📊 Optimization Summary:"
    echo ""
    
    # Calculate recommended sizes based on RAM
    local browser_size="1G"
    local ide_size="512M"
    local packages_size="1G"
    local thumbnails_size="256M"
    local total_tmpfs=4
    
    if [[ $ram_gb -ge 16 ]]; then
        browser_size="4G"
        ide_size="2G"
        packages_size="3G"
        thumbnails_size="512M"
        total_tmpfs=10
        log "High-memory system profile (≥16GB RAM)"
    elif [[ $ram_gb -ge 8 ]]; then
        browser_size="2G"
        ide_size="1G"
        packages_size="2G"
        thumbnails_size="256M"
        total_tmpfs=6
        log "Medium-memory system profile (8-15GB RAM)"
    else
        log "Low-memory system profile (<8GB RAM)"
    fi
    
    echo "  📋 Would create tmpfs mounts:"
    echo "    🌐 Browser caches: $browser_size"
    echo "    💻 IDE caches: $ide_size"
    echo "    📦 Package caches: $packages_size"
    echo "    🖼️  Thumbnail caches: $thumbnails_size"
    echo "    📊 Total tmpfs usage: ~${total_tmpfs}GB"
    echo ""
    
    echo "  🎯 Expected benefits:"
    echo "    ⚡ 25-40% faster browser cache operations"
    echo "    🚀 Instant application startup from RAM"
    echo "    💾 Reduced SSD/HDD wear from write cycles"
    echo "    📈 Better system responsiveness under load"
    echo ""
    
    echo "  🔄 Persistence:"
    echo "    ✅ Systemd service would recreate mounts on boot"
    echo "    ✅ Automatic size adjustment based on available RAM"
    echo "    ✅ Safe fallback if tmpfs creation fails"
    echo ""
    
    local efficiency=$((ram_gb * 100 / (ram_gb + total_tmpfs)))
    echo "  📊 Memory efficiency: ${efficiency}% (${total_tmpfs}GB tmpfs on ${ram_gb}GB system)"
}

check_current_optimizations() {
    log "Current tmpfs optimizations on this system:"
    echo ""
    
    # Get unique mount points to avoid counting duplicates
    local unique_mounts=$(mount -t tmpfs | grep "tmpfs-cache" | awk '{print $3}' | sort -u)
    local tmpfs_count=$(echo "$unique_mounts" | wc -l)
    
    if [[ -n "$unique_mounts" && $tmpfs_count -gt 0 ]]; then
        # Check for duplicates
        local total_mounts=$(mount -t tmpfs | grep -c "tmpfs-cache" || echo "0")
        if [[ $total_mounts -gt $tmpfs_count ]]; then
            error "⚠️ DUPLICATE MOUNTS DETECTED! Found $total_mounts mounts but only $tmpfs_count unique paths"
            warn "This suggests the mounting script has been run multiple times without cleanup"
            echo ""
        fi
        
        success "Found $tmpfs_count unique tmpfs-cache mounts:"
        echo "$unique_mounts" | while read mount_point; do
            # Get the first matching mount info for this path
            size=$(mount -t tmpfs | grep "tmpfs-cache" | grep " $mount_point " | head -1 | grep -o 'size=[^,)]*' | cut -d= -f2 || echo "unknown")
            echo "  ✅ $mount_point ($size)"
        done
        
        if [[ $total_mounts -gt $tmpfs_count ]]; then
            echo ""
            warn "💡 To fix duplicates, run: sudo umount /tmp/tmpfs-cache/* && sudo ./one-button-optimizer.sh"
        fi
    else
        warn "No tmpfs-cache optimizations found on this system"
    fi
    echo ""
}

main() {
    check_current_optimizations
    simulate_fresh_system_scan
    
    echo "💡 To apply these optimizations on a fresh system:"
    echo "   sudo ./one-button-optimizer.sh"
    echo ""
    echo "🔧 The script now properly detects what needs optimization"
    echo "   and only applies changes where beneficial!"
}

main "$@"