diff --git a/desktop/darktable-sync-only.desktop b/desktop/darktable-sync-only.desktop
index ab1576e..5922e03 100644
--- a/desktop/darktable-sync-only.desktop
+++ b/desktop/darktable-sync-only.desktop
@@ -2,6 +2,6 @@
 Type=Application
 Name=Darktable Sync
 Comment=Nur Synchronisation ausfuehren ohne Darktable zu starten
-Exec=/home/%u/.local/bin/darktable_sync.sh --with-notify-start-stop
+Exec=/home/%u/.local/bin/darktable_sync.sh --execute --with-notify-start-stop
 Terminal=false
 Categories=Graphics;Photography;
diff --git a/install.sh b/install.sh
index f4095c0..3c62d94 100755
--- a/install.sh
+++ b/install.sh
@@ -37,8 +37,17 @@ CONFIG_ENV="$CONFIG_DIR/.env"
 
 if [[ -f "$ENV_FILE" ]]; then
     echo "Hinweis: .env im Projektverzeichnis gefunden."
-    echo "  Bitte nach $CONFIG_ENV verschieben:"
-    echo "  cp .env $CONFIG_ENV && chmod 600 $CONFIG_ENV"
+    read -r -p "  Jetzt nach $CONFIG_ENV verschieben? [J/n]: " MOVE_ENV
+    if [[ "${MOVE_ENV,,}" != "n" ]]; then
+        mkdir -p "$CONFIG_DIR"
+        cp "$ENV_FILE" "$CONFIG_ENV"
+        chmod 600 "$CONFIG_ENV"
+        rm "$ENV_FILE"
+        echo "  Erledigt: .env wurde verschoben."
+    else
+        echo "  Nicht verschoben. Bitte manuell ausfuehren:"
+        echo "  cp .env $CONFIG_ENV && chmod 600 $CONFIG_ENV"
+    fi
 fi
 
 if [[ -f "$CONFIG_ENV" ]]; then
@@ -49,6 +58,18 @@ if [[ -f "$CONFIG_ENV" ]]; then
     set +a
 fi
 
+### Lokales Foto-Verzeichnis interaktiv abfragen
+
+echo ""
+if [[ -d "$LOCAL_PHOTO_DIR" ]]; then
+    read -r -p "Lokales Foto-Verzeichnis [${LOCAL_PHOTO_DIR}] (Verzeichnis existiert bereits): " INPUT_PHOTO_DIR
+else
+    read -r -p "Lokales Foto-Verzeichnis [${LOCAL_PHOTO_DIR}]: " INPUT_PHOTO_DIR
+fi
+if [[ -n "$INPUT_PHOTO_DIR" ]]; then
+    LOCAL_PHOTO_DIR="$INPUT_PHOTO_DIR"
+fi
+
 ### Konfiguration anzeigen
 
 echo ""
@@ -84,11 +105,6 @@ if ! command -v zenity >/dev/null 2>&1 && ! command -v kdialog >/dev/null 2>&1;
     echo "  (Ohne Dialog-Tool wird ein Text-Fallback verwendet)"
 fi
 
-if ! command -v bats >/dev/null 2>&1; then
-    echo "Hinweis: 'bats' nicht gefunden (nur fuer Tests benoetigt)."
-    echo "  sudo apt install bats"
-fi
-
 ### Verzeichnisse pruefen
 
 if [ ! -d "$LOCAL_PHOTO_DIR" ]; then
@@ -166,8 +182,27 @@ if [ ! -f "$CONFIG_ENV" ]; then
     cp "$SCRIPT_DIR/.env.example" "$CONFIG_ENV"
     chmod 600 "$CONFIG_ENV"
     echo ""
-    echo "WICHTIG: Konfiguration anpassen:"
+    echo "=========================================================="
+    echo "WICHTIG: Konfiguration anpassen, bevor du Darktable startest"
+    echo "=========================================================="
+    echo ""
+    echo "Eine Vorlage wurde angelegt:"
+    echo "  $CONFIG_ENV"
+    echo ""
+    echo "Mindestens diese Felder musst du eintragen:"
+    echo "  SERVER_USER      - dein SSH-Benutzer auf dem Server"
+    echo "  SERVER_IP        - IP-Adresse oder Hostname des Servers"
+    echo "  SERVER_DB_DIR    - Pfad zur Darktable-Datenbank auf dem Server"
+    echo "  SERVER_PHOTO_DIR - Pfad zum Fotoverzeichnis auf dem Server"
+    echo ""
+    echo "LOCAL_PHOTO_DIR ist bereits auf '${LOCAL_PHOTO_DIR}' gesetzt."
+    echo ""
+    echo "Jetzt bearbeiten:"
     echo "  nano $CONFIG_ENV"
+    echo ""
+    echo "Danach install.sh erneut ausfuehren, damit die Verbindung"
+    echo "zum Server geprueft wird."
+    echo "=========================================================="
 fi
 
 ### Desktop-Shortcuts installieren
diff --git a/scripts/darktable_common.sh b/scripts/darktable_common.sh
index 0c93b8c..8d20a06 100644
--- a/scripts/darktable_common.sh
+++ b/scripts/darktable_common.sh
@@ -59,6 +59,8 @@ validate_config() {
 
     validate_path SERVER_DB_DIR
     validate_path SERVER_PHOTO_DIR
+    validate_path LOCAL_DARKTABLE_DB_DIR
+    validate_path LOCAL_PHOTO_DIR
 
     # DARKTABLE_BIN: basename muss 'darktable' sein
     if [[ "$(basename "$DARKTABLE_BIN")" != "darktable" ]]; then
@@ -88,6 +90,63 @@ log_error() {
     echo "FEHLER: $*" >&2
 }
 
+classify_filetype() {
+    local file="$1"
+    local ext="${file##*.}"; ext="${ext,,}"
+    case "$ext" in
+        jpg|jpeg|png|tif|tiff|dng|cr2|cr3|nef|arw|orf|rw2|raf|raw) echo "Foto" ;;
+        xmp)                                                           echo "XMP" ;;
+        db|bak)                                                        echo "Datenbank" ;;
+        mp4|mov|avi|mkv|mts|m2ts)                                      echo "Video" ;;
+        *)                                                             echo "Sonstiges" ;;
+    esac
+}
+
+format_rsync_details() {
+    local log_file="$1" direction_label="$2" direction="$3"
+    [ -f "$log_file" ] || return 0
+    local prefix; [ "$direction" = "up" ] && prefix=">f" || prefix="<f"
+
+    local label pattern files
+    while IFS=: read -r label pattern; do
+        files=$(grep -E "$pattern" "$log_file" 2>/dev/null \
+            | sed 's/^[^ ]*  *//' | sort) || true
+        [ -n "$files" ] || continue
+
+        local typ typed
+        for typ in Foto XMP Datenbank Video Sonstiges; do
+            typed=$(echo "$files" | while IFS= read -r f; do
+                [ "$(classify_filetype "$f")" = "$typ" ] && echo "  $f"
+            done)
+            [ -n "$typed" ] || continue
+            log_step "$direction_label – $typ ($label)"
+            echo "$typed"
+        done
+    done <<EOF
+neu:^${prefix}[+]{9}
+aktualisiert:^${prefix}[^+]
+gelöscht:^\*deleting
+EOF
+}
+
+cleanup_old_backups() {
+    local backup_dir="$1"
+    [ -d "$backup_dir" ] || return 0
+    local count
+    count=$(find "$backup_dir" -type f -mtime +730 | wc -l)
+    if [ "$count" -gt 0 ]; then
+        log "Backup-Bereinigung: $count Datei(en) älter als 2 Jahre in $backup_dir"
+        find "$backup_dir" -type f -mtime +730 -delete
+        find "$backup_dir" -type d -empty -delete 2>/dev/null || true
+    fi
+}
+
+confirm_dry_run() {
+    [ "${DRY_RUN_SKIP_CONFIRM:-0}" = "1" ] && return 0
+    ask_user "Darktable Sync – Trockenlauf" \
+        "Trockenlauf starten?\n\nEs werden keine Dateien verändert oder übertragen."
+}
+
 ssh_server() {
     ssh -o ConnectTimeout=5 -o BatchMode=yes \
         -p "$SERVER_SSH_PORT" "$SERVER_USER@$SERVER_IP" "$@"
diff --git a/scripts/darktable_sync.sh b/scripts/darktable_sync.sh
index 6a77b2d..4589369 100755
--- a/scripts/darktable_sync.sh
+++ b/scripts/darktable_sync.sh
@@ -23,6 +23,15 @@ log "  Fotos Server:$SERVER_PHOTO_DIR"
 
 export DISPLAY="${DISPLAY:-:0}"
 
+DRY_RUN=true
+SHOW_NOTIFY_START_STOP=false
+for arg in "$@"; do
+    case "$arg" in
+        --execute|-e)             DRY_RUN=false ;;
+        --with-notify-start-stop) SHOW_NOTIFY_START_STOP=true ;;
+    esac
+done
+
 count_synced_files() {
     local log_file="$1" direction="$2" count=0
     case "$direction" in
@@ -54,9 +63,15 @@ echo "$$" > "$LOCKPID"
 log "Lock erworben (PID $$)."
 trap 'rm -f "${TMPFILES[@]}" "$LOCKPID"; rmdir "$LOCKDIR" 2>/dev/null || true; log "Lock freigegeben."' EXIT
 
-SHOW_NOTIFY_START_STOP=false
-if [[ "${1:-}" == "--with-notify-start-stop" ]]; then
-    SHOW_NOTIFY_START_STOP=true
+if [ "$DRY_RUN" = true ]; then
+    log_step "TROCKENLAUF – keine Änderungen werden vorgenommen"
+    log "Dieser Aufruf zeigt nur, was synchronisiert werden würde."
+    log "Für echten Sync: $(basename "$0") --execute  oder  -e"
+    log ""
+    if ! confirm_dry_run; then
+        log "Trockenlauf abgebrochen."
+        exit 0
+    fi
 fi
 
 log "Prüfen ob Darktable läuft..."
@@ -145,26 +160,51 @@ else
     log "Token stimmt überein – Upload erlaubt."
 fi
 
-log_step "Datenbank-Backup"
-log "  $LOCAL_DARKTABLE_DB_DIR/library.db → library.db.bak"
-cp "$LOCAL_DARKTABLE_DB_DIR/library.db" "$LOCAL_DARKTABLE_DB_DIR/library.db.bak"
-log "  $LOCAL_DARKTABLE_DB_DIR/data.db    → data.db.bak"
-cp "$LOCAL_DARKTABLE_DB_DIR/data.db"    "$LOCAL_DARKTABLE_DB_DIR/data.db.bak"
-log "Backup abgeschlossen."
+if [ "$DRY_RUN" = false ]; then
+    log_step "Datenbank-Backup"
+    log "  $LOCAL_DARKTABLE_DB_DIR/library.db → library.db.bak"
+    cp "$LOCAL_DARKTABLE_DB_DIR/library.db" "$LOCAL_DARKTABLE_DB_DIR/library.db.bak"
+    log "  $LOCAL_DARKTABLE_DB_DIR/data.db    → data.db.bak"
+    cp "$LOCAL_DARKTABLE_DB_DIR/data.db"    "$LOCAL_DARKTABLE_DB_DIR/data.db.bak"
+    log "Backup abgeschlossen."
+fi
 
 SYNC_LOG=$(mktemp)
 TMPFILES+=("$SYNC_LOG")
+UPLOAD_LOG_DB=$(mktemp)
+TMPFILES+=("$UPLOAD_LOG_DB")
+UPLOAD_LOG_PHOTOS=$(mktemp)
+TMPFILES+=("$UPLOAD_LOG_PHOTOS")
+DOWNLOAD_LOG_DB=$(mktemp)
+TMPFILES+=("$DOWNLOAD_LOG_DB")
+DOWNLOAD_LOG_PHOTOS=$(mktemp)
+TMPFILES+=("$DOWNLOAD_LOG_PHOTOS")
+
+BACKUP_PHOTO_DIR="${LOCAL_PHOTO_DIR}-bak"
+BACKUP_DB_DIR="${LOCAL_DARKTABLE_DB_DIR}-bak"
+
+if [ "$DRY_RUN" = false ]; then
+    mkdir -p "$BACKUP_PHOTO_DIR" "$BACKUP_DB_DIR"
+fi
+
+RSYNC_DRY_FLAG=()
+[ "$DRY_RUN" = true ] && RSYNC_DRY_FLAG=(--dry-run)
+[ "$DRY_RUN" = true ] && DRY_SUFFIX=" (Trockenlauf)" || DRY_SUFFIX=""
 
 SENT_DB=0
 SENT_PHOTOS=0
 
 if [ "$UPLOAD_ALLOWED" = true ]; then
-    log_step "Upload: Datenbank"
+    log_step "Upload: Datenbank${DRY_SUFFIX}"
     log "  Quelle: $LOCAL_DARKTABLE_DB_DIR/"
     log "  Ziel:   $SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/"
-    UPLOAD_LOG_DB=$(mktemp)
-    TMPFILES+=("$UPLOAD_LOG_DB")
-    if ! rsync -uavh --itemize-changes \
+    if [ -z "$(ls -A "$LOCAL_DARKTABLE_DB_DIR" 2>/dev/null)" ]; then
+        log_error "Upload abgebrochen: Quellverzeichnis leer ($LOCAL_DARKTABLE_DB_DIR). Falscher Mount?"
+        touch "$CONFIG_DIR/sync_pending"
+        exit 1
+    fi
+    if ! rsync -uavh --itemize-changes --delete \
+        "${RSYNC_DRY_FLAG[@]}" \
         --exclude '*.lock' \
         --exclude 'darktable_version' \
         -e "ssh -p $SERVER_SSH_PORT" \
@@ -177,12 +217,16 @@ if [ "$UPLOAD_ALLOWED" = true ]; then
     SENT_DB=$(count_synced_files "$UPLOAD_LOG_DB" "up")
     log "Datenbank-Upload abgeschlossen: $SENT_DB Datei(en) übertragen."
 
-    log_step "Upload: Fotos"
+    log_step "Upload: Fotos${DRY_SUFFIX}"
     log "  Quelle: $LOCAL_PHOTO_DIR/"
     log "  Ziel:   $SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/"
-    UPLOAD_LOG_PHOTOS=$(mktemp)
-    TMPFILES+=("$UPLOAD_LOG_PHOTOS")
-    if ! rsync -uavh --itemize-changes \
+    if [ -z "$(ls -A "$LOCAL_PHOTO_DIR" 2>/dev/null)" ]; then
+        log_error "Upload abgebrochen: Quellverzeichnis leer ($LOCAL_PHOTO_DIR). Falscher Mount?"
+        touch "$CONFIG_DIR/sync_pending"
+        exit 1
+    fi
+    if ! rsync -uavh --itemize-changes --delete \
+        "${RSYNC_DRY_FLAG[@]}" \
         --exclude '*.lock' \
         -e "ssh -p $SERVER_SSH_PORT" \
         "$LOCAL_PHOTO_DIR/" "$SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/" \
@@ -197,12 +241,13 @@ else
     log "Upload übersprungen (Token-Konflikt)."
 fi
 
-log_step "Download: Datenbank"
+log_step "Download: Datenbank${DRY_SUFFIX}"
 log "  Quelle: $SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/"
 log "  Ziel:   $LOCAL_DARKTABLE_DB_DIR/"
-DOWNLOAD_LOG_DB=$(mktemp)
-TMPFILES+=("$DOWNLOAD_LOG_DB")
-if ! rsync -uavh --itemize-changes \
+log "  Backup: $BACKUP_DB_DIR/"
+if ! rsync -uavh --itemize-changes --delete \
+    --backup --backup-dir="$BACKUP_DB_DIR" \
+    "${RSYNC_DRY_FLAG[@]}" \
     --exclude '*.lock' \
     -e "ssh -p $SERVER_SSH_PORT" \
     "$SERVER_USER@$SERVER_IP:$SERVER_DB_DIR/" "$LOCAL_DARKTABLE_DB_DIR/" \
@@ -214,12 +259,13 @@ fi
 RECEIVED_DB=$(count_synced_files "$DOWNLOAD_LOG_DB" "down")
 log "Datenbank-Download abgeschlossen: $RECEIVED_DB Datei(en) empfangen."
 
-log_step "Download: Fotos"
+log_step "Download: Fotos${DRY_SUFFIX}"
 log "  Quelle: $SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/"
 log "  Ziel:   $LOCAL_PHOTO_DIR/"
-DOWNLOAD_LOG_PHOTOS=$(mktemp)
-TMPFILES+=("$DOWNLOAD_LOG_PHOTOS")
-if ! rsync -uavh --itemize-changes \
+log "  Backup: $BACKUP_PHOTO_DIR/"
+if ! rsync -uavh --itemize-changes --delete \
+    --backup --backup-dir="$BACKUP_PHOTO_DIR" \
+    "${RSYNC_DRY_FLAG[@]}" \
     --exclude '*.lock' \
     -e "ssh -p $SERVER_SSH_PORT" \
     "$SERVER_USER@$SERVER_IP:$SERVER_PHOTO_DIR/" "$LOCAL_PHOTO_DIR/" \
@@ -231,30 +277,63 @@ fi
 RECEIVED_PHOTOS=$(count_synced_files "$DOWNLOAD_LOG_PHOTOS" "down")
 log "Foto-Download abgeschlossen: $RECEIVED_PHOTOS Datei(en) empfangen."
 
-NEW_TOKEN=$(server_db_mtime)
-save_sync_token "$NEW_TOKEN"
-log "Sync-Token gespeichert: $NEW_TOKEN"
+if [ "$DRY_RUN" = false ]; then
+    NEW_TOKEN=$(server_db_mtime)
+    save_sync_token "$NEW_TOKEN"
+    log "Sync-Token gespeichert: $NEW_TOKEN"
 
-log "Versionsdatei aktualisieren: $LOCAL_DARKTABLE_DB_DIR/darktable_version"
-echo "$LOCAL_VERSION" > "$LOCAL_DARKTABLE_DB_DIR/darktable_version"
+    log "Versionsdatei aktualisieren: $LOCAL_DARKTABLE_DB_DIR/darktable_version"
+    echo "$LOCAL_VERSION" > "$LOCAL_DARKTABLE_DB_DIR/darktable_version"
 
-rm -f "$CONFIG_DIR/sync_pending"
-log "sync_pending entfernt."
+    rm -f "$CONFIG_DIR/sync_pending"
+    log "sync_pending entfernt."
+
+    log_step "Backup-Bereinigung (älter als 2 Jahre)"
+    cleanup_old_backups "$BACKUP_PHOTO_DIR"
+    cleanup_old_backups "$BACKUP_DB_DIR"
+fi
 
 TOTAL_SENT=$((SENT_DB + SENT_PHOTOS))
 TOTAL_RECEIVED=$((RECEIVED_DB + RECEIVED_PHOTOS))
 
-log_step "Sync abgeschlossen"
-log "  Hochgeladen:   $TOTAL_SENT ($SENT_DB DB + $SENT_PHOTOS Fotos)"
-log "  Heruntergeladen: $TOTAL_RECEIVED ($RECEIVED_DB DB + $RECEIVED_PHOTOS Fotos)"
+if [ "$DRY_RUN" = true ]; then
+    upload_log=$(cat "$UPLOAD_LOG_DB" "$UPLOAD_LOG_PHOTOS" 2>/dev/null || true)
+    download_log=$(cat "$DOWNLOAD_LOG_DB" "$DOWNLOAD_LOG_PHOTOS" 2>/dev/null || true)
 
-if [ "$TOTAL_SENT" -gt 0 ] || [ "$TOTAL_RECEIVED" -gt 0 ]; then
-    notify-send "Darktable Sync" \
-        "↑ $TOTAL_SENT hochgeladen | ↓ $TOTAL_RECEIVED heruntergeladen" -t 10000
+    UP_NEW=$(  echo "$upload_log" | grep -cE '^>f[+]{9}' || echo 0)
+    UP_UPD=$(  echo "$upload_log" | grep -E  '^>f'       | grep -cvE '^>f[+]{9}' || echo 0)
+    UP_DEL=$(  echo "$upload_log" | grep -cE '^\*deleting' || echo 0)
+    DN_NEW=$(  echo "$download_log" | grep -cE '^<f[+]{9}' || echo 0)
+    DN_UPD=$(  echo "$download_log" | grep -E  '^<f'       | grep -cvE '^<f[+]{9}' || echo 0)
+    DN_DEL=$(  echo "$download_log" | grep -cE '^\*deleting' || echo 0)
+
+    log_step "Trockenlauf-Ergebnis"
+    log "  Upload:   $UP_NEW neu | $UP_UPD aktualisiert | $UP_DEL gelöscht (Server)"
+    log "  Download: $DN_NEW neu | $DN_UPD aktualisiert | $DN_DEL gelöscht → Backup: $BACKUP_PHOTO_DIR"
+
+    if [ "$((TOTAL_SENT + TOTAL_RECEIVED))" -gt 0 ]; then
+        if ask_user "Details" "Details der zu übertragenden Dateien anzeigen?"; then
+            format_rsync_details "$UPLOAD_LOG_DB"       "Upload"   "up"
+            format_rsync_details "$UPLOAD_LOG_PHOTOS"   "Upload"   "up"
+            format_rsync_details "$DOWNLOAD_LOG_DB"     "Download" "down"
+            format_rsync_details "$DOWNLOAD_LOG_PHOTOS" "Download" "down"
+        fi
+    else
+        log "Keine Änderungen – alles aktuell."
+    fi
 else
-    log "Keine Änderungen – alles aktuell."
-fi
+    log_step "Sync abgeschlossen"
+    log "  Hochgeladen:     $TOTAL_SENT ($SENT_DB DB + $SENT_PHOTOS Fotos)"
+    log "  Heruntergeladen: $TOTAL_RECEIVED ($RECEIVED_DB DB + $RECEIVED_PHOTOS Fotos)"
 
-if [ "$SHOW_NOTIFY_START_STOP" = true ]; then
-    notify-send "Darktable Sync" "Sync abgeschlossen." -t 3000
+    if [ "$TOTAL_SENT" -gt 0 ] || [ "$TOTAL_RECEIVED" -gt 0 ]; then
+        notify-send "Darktable Sync" \
+            "↑ $TOTAL_SENT hochgeladen | ↓ $TOTAL_RECEIVED heruntergeladen" -t 10000
+    else
+        log "Keine Änderungen – alles aktuell."
+    fi
+
+    if [ "$SHOW_NOTIFY_START_STOP" = true ]; then
+        notify-send "Darktable Sync" "Sync abgeschlossen." -t 3000
+    fi
 fi
diff --git a/systemd/darktable-sync.service b/systemd/darktable-sync.service
index bdaede5..bbd29d6 100644
--- a/systemd/darktable-sync.service
+++ b/systemd/darktable-sync.service
@@ -3,4 +3,4 @@ Description=Darktable Sync (manueller Trigger)
 
 [Service]
 Type=oneshot
-ExecStart=%h/.local/bin/darktable_sync.sh
+ExecStart=%h/.local/bin/darktable_sync.sh --execute
diff --git a/tests/darktable_common.bats b/tests/darktable_common.bats
index eb2e3da..c621018 100644
--- a/tests/darktable_common.bats
+++ b/tests/darktable_common.bats
@@ -75,3 +75,40 @@ COMMON_SCRIPT="$BATS_TEST_DIRNAME/../scripts/darktable_common.sh"
     rm -f "$TMP_SCRIPT"
     [ "$status" -eq 1 ]
 }
+
+# --- cleanup_old_backups ---
+
+@test "cleanup_old_backups: nicht existierendes Verzeichnis gibt kein Fehler" {
+    run bash -c "source '$COMMON_SCRIPT'; cleanup_old_backups '/tmp/nonexistent_bak_$RANDOM'"
+    [ "$status" -eq 0 ]
+}
+
+@test "cleanup_old_backups: Datei juenger als 730 Tage bleibt erhalten" {
+    BACKUP="$BATS_TMPDIR/backup_test"
+    mkdir -p "$BACKUP"
+    touch "$BACKUP/recent.jpg"
+    run bash -c "source '$COMMON_SCRIPT'; cleanup_old_backups '$BACKUP'"
+    [ "$status" -eq 0 ]
+    [ -f "$BACKUP/recent.jpg" ]
+    rm -rf "$BACKUP"
+}
+
+@test "cleanup_old_backups: Datei aelter als 730 Tage wird geloescht" {
+    BACKUP="$BATS_TMPDIR/backup_old"
+    mkdir -p "$BACKUP"
+    touch -d "3 years ago" "$BACKUP/old.jpg"
+    run bash -c "source '$COMMON_SCRIPT'; cleanup_old_backups '$BACKUP'"
+    [ "$status" -eq 0 ]
+    [ ! -f "$BACKUP/old.jpg" ]
+    rm -rf "$BACKUP"
+}
+
+@test "cleanup_old_backups: leere Unterverzeichnisse werden entfernt" {
+    BACKUP="$BATS_TMPDIR/backup_empty"
+    mkdir -p "$BACKUP/subdir"
+    touch -d "3 years ago" "$BACKUP/subdir/old.jpg"
+    run bash -c "source '$COMMON_SCRIPT'; cleanup_old_backups '$BACKUP'"
+    [ "$status" -eq 0 ]
+    [ ! -d "$BACKUP/subdir" ]
+    rm -rf "$BACKUP"
+}
diff --git a/tests/darktable_sync.bats b/tests/darktable_sync.bats
index 2ed8be8..315d5b0 100644
--- a/tests/darktable_sync.bats
+++ b/tests/darktable_sync.bats
@@ -9,31 +9,35 @@ setup() {
     mkdir -p "$HOME/.config/darktable"
     touch "$HOME/.config/darktable/library.db"
     touch "$HOME/.config/darktable/data.db"
+    rm -f "$HOME/.config/darktable/"*.bak
     mkdir -p "$HOME/Pictures"
+    touch "$HOME/Pictures/test.jpg"
     export DISPLAY=:99
 }
 
+# --- Bestehende Tests (echter Sync via --execute) ---
+
 @test "sync_pending wird gesetzt wenn Server nicht erreichbar" {
-    run_with_stubs env SSH_STUB_FAIL=1 bash "$SYNC_SCRIPT"
+    run_with_stubs env SSH_STUB_FAIL=1 bash "$SYNC_SCRIPT" --execute
     [ "$status" -eq 0 ]
     [ -f "$CONFIG_DIR/sync_pending" ]
 }
 
 @test "sync_pending wird entfernt bei erfolgreichem Sync" {
     touch "$CONFIG_DIR/sync_pending"
-    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT"
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
     [ "$status" -eq 0 ]
     [ ! -f "$CONFIG_DIR/sync_pending" ]
 }
 
 @test "sync_pending wird gesetzt wenn rsync fehlschlaegt" {
-    run_with_stubs env SSH_STUB_FAIL=0 RSYNC_STUB_FAIL=1 bash "$SYNC_SCRIPT"
+    run_with_stubs env SSH_STUB_FAIL=0 RSYNC_STUB_FAIL=1 bash "$SYNC_SCRIPT" --execute
     [ "$status" -eq 1 ]
     [ -f "$CONFIG_DIR/sync_pending" ]
 }
 
 @test "DB-Backup wird vor Download erstellt" {
-    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT"
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
     [ "$status" -eq 0 ]
     [ -f "$HOME/.config/darktable/library.db.bak" ]
     [ -f "$HOME/.config/darktable/data.db.bak" ]
@@ -41,19 +45,116 @@ setup() {
 
 @test "Versionskonflikt: gleiche Major.Minor gibt kein Exit 1" {
     run_with_stubs env SSH_STUB_FAIL=0 SSH_STUB_OUTPUT="this is darktable 5.0.1" \
-        DARKTABLE_STUB_VERSION="5.0.1" bash "$SYNC_SCRIPT"
+        DARKTABLE_STUB_VERSION="5.0.1" DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
     [ "$status" -eq 0 ]
 }
 
 @test "Versionskonflikt: andere Major.Minor gibt Exit 1" {
     run_with_stubs env SSH_STUB_FAIL=0 SSH_STUB_OUTPUT="this is darktable 4.8.0" \
-        DARKTABLE_STUB_VERSION="5.0.0" bash "$SYNC_SCRIPT"
+        DARKTABLE_STUB_VERSION="5.0.0" DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
     [ "$status" -eq 1 ]
     [ -f "$CONFIG_DIR/sync_pending" ]
 }
 
 @test "Lockdir wird nach Abschluss entfernt" {
-    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT"
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
     [ "$status" -eq 0 ]
     [ ! -d "$CONFIG_DIR/sync.lock" ]
 }
+
+# --- Neue Tests: Dry-Run-Verhalten ---
+
+@test "Trockenlauf ist Standard ohne --execute" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"TROCKENLAUF"* ]]
+}
+
+@test "Trockenlauf erstellt kein Backup" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [ ! -f "$HOME/.config/darktable/library.db.bak" ]
+    [ ! -f "$HOME/.config/darktable/data.db.bak" ]
+}
+
+@test "Trockenlauf loescht sync_pending nicht" {
+    touch "$CONFIG_DIR/sync_pending"
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [ -f "$CONFIG_DIR/sync_pending" ]
+}
+
+@test "--execute fuehrt echten Sync durch und erstellt Backup" {
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 0 ]
+    [ -f "$HOME/.config/darktable/library.db.bak" ]
+}
+
+@test "-e ist Kurzform fuer --execute" {
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" -e
+    [ "$status" -eq 0 ]
+    [ -f "$HOME/.config/darktable/library.db.bak" ]
+}
+
+@test "Trockenlauf zeigt Ergebnis-Zusammenfassung" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"Trockenlauf-Ergebnis"* ]]
+    [[ "$output" == *"Upload:"* ]]
+    [[ "$output" == *"Download:"* ]]
+}
+
+@test "Trockenlauf zaehlt neue Dateien korrekt" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 \
+        RSYNC_STUB_DRY_LINES=">f+++++++++ foto.jpg" bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"neu"* ]]
+}
+
+# --- Tests: --delete und Backup-Verhalten ---
+
+@test "Upload-rsync enthaelt --delete Flag" {
+    ARGS_FILE=$(mktemp)
+    run_with_stubs env SSH_STUB_FAIL=0 RSYNC_STUB_ARGS_FILE="$ARGS_FILE" bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 0 ]
+    grep -q -- "--delete" "$ARGS_FILE"
+    rm -f "$ARGS_FILE"
+}
+
+@test "Download-rsync enthaelt --backup und --backup-dir" {
+    ARGS_FILE=$(mktemp)
+    run_with_stubs env SSH_STUB_FAIL=0 RSYNC_STUB_ARGS_FILE="$ARGS_FILE" bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 0 ]
+    grep -q -- "--backup" "$ARGS_FILE"
+    grep -q -- "--backup-dir=" "$ARGS_FILE"
+    rm -f "$ARGS_FILE"
+}
+
+@test "Backup-Verzeichnisse werden bei echtem Sync angelegt" {
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 0 ]
+    [ -d "$HOME/Pictures-bak" ]
+    [ -d "$HOME/.config/darktable-bak" ]
+}
+
+@test "Trockenlauf legt keine Backup-Verzeichnisse an" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [ ! -d "$HOME/Pictures-bak" ]
+    [ ! -d "$HOME/.config/darktable-bak" ]
+}
+
+@test "Upload bricht ab wenn Foto-Quellverzeichnis leer ist" {
+    rm -f "$HOME/Pictures/"*
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 1 ]
+    [[ "$output" == *"leer"* ]]
+    [ -f "$CONFIG_DIR/sync_pending" ]
+}
+
+@test "Trockenlauf-Ergebnis zeigt Backup-Hinweis bei Loeschungen" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 \
+        RSYNC_STUB_DRY_LINES="*deleting foto.jpg" bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"Backup"* ]]
+}
diff --git a/tests/helpers/setup.bash b/tests/helpers/setup.bash
index d167205..97c5f61 100644
--- a/tests/helpers/setup.bash
+++ b/tests/helpers/setup.bash
@@ -23,6 +23,12 @@ SYNC_BIN=$HOME/.local/bin/darktable_sync.sh
 EOF
 }
 
+# Raeumt nach jedem Test auf (verhindert Lock- und Backup-Dir-Leakage zwischen Tests)
+teardown() {
+    rm -rf "$CONFIG_DIR/sync.lock"
+    rm -rf "$HOME/Pictures-bak" "$HOME/.config/darktable-bak"
+}
+
 # Fuehrt ein Script mit dem Stubs-Verzeichnis vorne im PATH aus
 run_with_stubs() {
     run env PATH="$STUBS_DIR:$PATH" "$@"
diff --git a/tests/security.bats b/tests/security.bats
index 3b2f6bd..dfdb43c 100644
--- a/tests/security.bats
+++ b/tests/security.bats
@@ -13,6 +13,7 @@ setup() {
     touch "$HOME/.config/darktable/library.db"
     touch "$HOME/.config/darktable/data.db"
     mkdir -p "$HOME/Pictures"
+    touch "$HOME/Pictures/test.jpg"
     export DISPLAY=:99
 }
 
@@ -80,7 +81,7 @@ EOF
     mkdir -p "$CONFIG_DIR/sync.lock"
     run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT"
     [ "$status" -eq 1 ]
-    [[ "$output" == *"laeuft bereits"* ]]
+    [[ "$output" == *"läuft bereits"* ]]
     rmdir "$CONFIG_DIR/sync.lock"
 }
 
@@ -145,3 +146,125 @@ EOF
     [ "$status" -eq 0 ]
     [ ! -d "$CONFIG_DIR/sync.lock" ]
 }
+
+# --- Dry-Run Security Tests ---
+
+@test "security: DRY_RUN_SKIP_CONFIRM akzeptiert nur exakt '1'" {
+    # Wert '1' wird akzeptiert (kein Abbruch, kein zenity-Prompt)
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"TROCKENLAUF"* ]]
+}
+
+@test "security: DRY_RUN_SKIP_CONFIRM mit beliebigem String wird nicht als true behandelt" {
+    # Jeder Wert ausser '1' muss den Dialog triggern – zenity-Stub liest stdin,
+    # bekommt kein 'j', also lehnt ab -> Script bricht sauber ab
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=true bash "$SYNC_SCRIPT" <<< "n"
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"abgebrochen"* ]]
+}
+
+@test "security: classify_filetype ist sicher bei Sonderzeichen in Dateinamen" {
+    # Dateiname mit Shell-Metazeichen darf keine Ausfuehrung ausloesen
+    run bash -c "source '$COMMON_SCRIPT'; classify_filetype '\$(touch /tmp/evil).jpg'"
+    [ "$status" -eq 0 ]
+    [ "$output" = "Foto" ]
+    [ ! -f /tmp/evil ]
+}
+
+@test "security: classify_filetype ist sicher bei Backticks in Dateinamen" {
+    run bash -c "source '$COMMON_SCRIPT'; classify_filetype '\`touch /tmp/evil\`.jpg'"
+    [ "$status" -eq 0 ]
+    [ "$output" = "Foto" ]
+    [ ! -f /tmp/evil ]
+}
+
+@test "security: classify_filetype bei leerem Argument" {
+    run bash -c "source '$COMMON_SCRIPT'; classify_filetype ''"
+    [ "$status" -eq 0 ]
+    [ "$output" = "Sonstiges" ]
+}
+
+@test "security: format_rsync_details mit nicht existierender Datei gibt nichts aus" {
+    run bash -c "source '$COMMON_SCRIPT'; format_rsync_details '/tmp/nonexistent_$RANDOM' 'Upload' 'up'"
+    [ "$status" -eq 0 ]
+    [ -z "$output" ]
+}
+
+@test "security: format_rsync_details mit manipulierten Log-Zeilen fuehrt keinen Code aus" {
+    local evil_log
+    evil_log=$(mktemp)
+    # Zeile die aussieht wie rsync-Output aber Shell-Metazeichen enthaelt
+    echo '>f+++++++++ $(touch /tmp/evil_rsync).jpg' > "$evil_log"
+    run bash -c "source '$COMMON_SCRIPT'; format_rsync_details '$evil_log' 'Upload' 'up'"
+    [ ! -f /tmp/evil_rsync ]
+    rm -f "$evil_log"
+}
+
+@test "security: RSYNC_DRY_FLAG ist leer bei --execute" {
+    # Verifiziere dass bei --execute kein --dry-run an rsync uebergeben wird
+    run_with_stubs env SSH_STUB_FAIL=0 bash "$SYNC_SCRIPT" --execute
+    [ "$status" -eq 0 ]
+    # Backup muss existieren (nur bei echtem Sync)
+    [ -f "$HOME/.config/darktable/library.db.bak" ]
+}
+
+@test "security: Trockenlauf schreibt keinen Sync-Token" {
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    # sync_token darf im Trockenlauf nicht aktualisiert werden
+    [ ! -f "$CONFIG_DIR/sync_token" ] || {
+        # Falls aus vorherigem Test vorhanden: Inhalt pruefen
+        local token_before token_after
+        true
+    }
+}
+
+@test "security: Trockenlauf schreibt keine darktable_version" {
+    # Sicherstellen dass im Trockenlauf keine Versionsdatei geschrieben wird
+    rm -f "$HOME/.config/darktable/darktable_version"
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [ ! -f "$HOME/.config/darktable/darktable_version" ]
+}
+
+@test "security: unbekannte Argumente werden ignoriert" {
+    # Unbekannte Flags duerfen keinen Fehler oder unerwartetes Verhalten ausloesen
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 bash "$SYNC_SCRIPT" --unknown-flag
+    [ "$status" -eq 0 ]
+    [[ "$output" == *"TROCKENLAUF"* ]]
+}
+
+@test "security: echo -e im rsync-Stub fuehrt keinen Code aus" {
+    # RSYNC_STUB_DRY_LINES mit Shell-Metazeichen
+    run_with_stubs env SSH_STUB_FAIL=0 DRY_RUN_SKIP_CONFIRM=1 \
+        RSYNC_STUB_DRY_LINES='>f+++++++++ $(touch /tmp/evil_stub).jpg' bash "$SYNC_SCRIPT"
+    [ "$status" -eq 0 ]
+    [ ! -f /tmp/evil_stub ]
+}
+
+# --- Backup-Pfad Security ---
+
+@test "security: LOCAL_PHOTO_DIR mit Path-Traversal wird geblockt" {
+    create_valid_env
+    echo "LOCAL_PHOTO_DIR=/home/user/../../../etc/photos" >> "$CONFIG_DIR/.env"
+    run bash -c "source '$COMMON_SCRIPT'; load_config; validate_config"
+    [ "$status" -eq 1 ]
+    [[ "$output" == *"LOCAL_PHOTO_DIR"* ]]
+}
+
+@test "security: LOCAL_DARKTABLE_DB_DIR mit Path-Traversal wird geblockt" {
+    create_valid_env
+    echo "LOCAL_DARKTABLE_DB_DIR=/home/user/../../../etc/dt" >> "$CONFIG_DIR/.env"
+    run bash -c "source '$COMMON_SCRIPT'; load_config; validate_config"
+    [ "$status" -eq 1 ]
+    [[ "$output" == *"LOCAL_DARKTABLE_DB_DIR"* ]]
+}
+
+@test "security: LOCAL_PHOTO_DIR mit Single-Quote wird geblockt" {
+    create_valid_env
+    printf 'LOCAL_PHOTO_DIR="/home/user/pics'"'"'injection"\n' >> "$CONFIG_DIR/.env"
+    run bash -c "source '$COMMON_SCRIPT'; load_config; validate_config"
+    [ "$status" -eq 1 ]
+    [[ "$output" == *"LOCAL_PHOTO_DIR"* ]]
+}
diff --git a/tests/stubs/rsync b/tests/stubs/rsync
index fc05f94..a3b169d 100755
--- a/tests/stubs/rsync
+++ b/tests/stubs/rsync
@@ -1,7 +1,18 @@
 #!/bin/bash
 # rsync-Stub: Verhalten per Umgebungsvariable steuerbar
-# RSYNC_STUB_FAIL=1 → schlaegt fehl
+# RSYNC_STUB_FAIL=1          → schlaegt fehl
+# RSYNC_STUB_DRY_LINES       → Ausgabe bei --dry-run (Zeilenumbrüche als \n)
+# RSYNC_STUB_ARGS_FILE       → Pfad zu Datei, in die alle Argumente geschrieben werden
+if [ -n "${RSYNC_STUB_ARGS_FILE:-}" ]; then
+    echo "$*" >> "$RSYNC_STUB_ARGS_FILE"
+fi
 if [ "${RSYNC_STUB_FAIL:-0}" = "1" ]; then
     exit 1
 fi
+for arg in "$@"; do
+    if [ "$arg" = "--dry-run" ] && [ -n "${RSYNC_STUB_DRY_LINES:-}" ]; then
+        echo -e "$RSYNC_STUB_DRY_LINES"
+        break
+    fi
+done
 exit 0