diff --git a/README.md b/README.md
index 7fa7a37..ccbb111 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,29 @@ cp .env.example .env
 ```bash
 ./scripts/test.sh
 ```
+## Move Nextcloud data directory to external storage
+Use the migration helper to move existing data to a host path and switch the app to a bind mount.
+Default target:
+- `/media/rbhat/DATA/nextcloud/NextCloudData`
+Run migration:
+```bash
+./scripts/migrate-data-directory.sh /media/rbhat/DATA/nextcloud/NextCloudData
+```
+What the script does:
+- enables maintenance mode
+- copies current `/var/www/html/data` content to target directory
+- applies owner/group and permissions for Nextcloud (`www-data`)
+- updates `docker-compose.yml` app volume with `...:/var/www/html/data`
+- recreates `app` and `web` services
+- disables maintenance mode and verifies mount
+Rollback (if needed):
+1. Remove the `:/var/www/html/data` bind mount line from `app` volumes in `docker-compose.yml`.
+2. `docker compose up -d app web`
+3. Confirm status:
+```bash
+docker exec --user www-data nextcloud-app php occ status
+```
+
 ## Production TLS (Let's Encrypt + Cloudflare DNS-01)
 1. Export credentials in shell:
 ```bash
diff --git a/docker-compose.yml b/docker-compose.yml
index 7dabfdc..511416f 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -42,6 +42,7 @@ services:
       - db
     volumes:
       - nextcloud_data:/var/www/html
+      - /media/rbhat/DATA/nextcloud/NextCloudData:/var/www/html/data
     networks:
       - nextcloud-net
 
diff --git a/scripts/migrate-data-directory.sh b/scripts/migrate-data-directory.sh
new file mode 100755
index 0000000..696fe9f
--- /dev/null
+++ b/scripts/migrate-data-directory.sh
@@ -0,0 +1,170 @@
+#!/usr/bin/env bash
+# scripts/migrate-data-directory.sh
+# Migrate Nextcloud data directory content to an external host path and
+# update docker-compose app volume mapping to use that path.
+
+set -euo pipefail
+
+REPO_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+COMPOSE_FILE="${REPO_DIR}/docker-compose.yml"
+APP_CONTAINER="${NEXTCLOUD_APP_CONTAINER:-nextcloud-app}"
+TARGET_DATA_DIR="${1:-/media/rbhat/DATA/nextcloud/NextCloudData}"
+
+if [ "${TARGET_DATA_DIR}" = "-h" ] || [ "${TARGET_DATA_DIR}" = "--help" ]; then
+  echo "Usage: ./scripts/migrate-data-directory.sh [target_data_dir]"
+  echo ""
+  echo "Default target: /media/rbhat/DATA/nextcloud/NextCloudData"
+  exit 0
+fi
+
+if ! command -v docker >/dev/null 2>&1; then
+  echo "ERROR: docker is required but not installed."
+  exit 1
+fi
+
+if ! command -v python3 >/dev/null 2>&1; then
+  echo "ERROR: python3 is required but not installed."
+  exit 1
+fi
+
+if [ ! -f "${COMPOSE_FILE}" ]; then
+  echo "ERROR: Compose file not found at ${COMPOSE_FILE}"
+  exit 1
+fi
+
+if ! docker ps --format '{{.Names}}' | grep -qx "${APP_CONTAINER}"; then
+  echo "ERROR: Container '${APP_CONTAINER}' is not running."
+  echo "Start the stack first (docker compose up -d)."
+  exit 1
+fi
+
+compose() {
+  if docker compose version >/dev/null 2>&1; then
+    docker compose -f "${COMPOSE_FILE}" "$@"
+  else
+    docker-compose -f "${COMPOSE_FILE}" "$@"
+  fi
+}
+
+wait_for_occ() {
+  local max_attempts=30
+  local attempt=1
+  while [ "${attempt}" -le "${max_attempts}" ]; do
+    if docker exec --user www-data "${APP_CONTAINER}" php occ status >/dev/null 2>&1; then
+      return 0
+    fi
+    sleep 2
+    attempt=$((attempt + 1))
+  done
+  return 1
+}
+
+if ! mkdir -p "${TARGET_DATA_DIR}" 2>/dev/null; then
+  if command -v sudo >/dev/null 2>&1; then
+    sudo mkdir -p "${TARGET_DATA_DIR}"
+  else
+    echo "ERROR: Unable to create ${TARGET_DATA_DIR}. Run as a user with write permission."
+    exit 1
+  fi
+fi
+
+CURRENT_BIND_SOURCE="$(docker inspect "${APP_CONTAINER}" --format '{{range .Mounts}}{{if eq .Destination "/var/www/html/data"}}{{.Source}}{{end}}{{end}}')"
+
+maintenance_enabled=0
+cleanup() {
+  if [ "${maintenance_enabled}" -eq 1 ]; then
+    docker exec --user www-data "${APP_CONTAINER}" php occ maintenance:mode --off >/dev/null 2>&1 || true
+  fi
+}
+trap cleanup EXIT
+
+echo "==> Enabling Nextcloud maintenance mode..."
+docker exec --user www-data "${APP_CONTAINER}" php occ maintenance:mode --on >/dev/null
+maintenance_enabled=1
+
+if [ "${CURRENT_BIND_SOURCE}" = "${TARGET_DATA_DIR}" ]; then
+  echo "==> App already mounted to target data directory; skipping data copy."
+else
+  echo "==> Copying data from running Nextcloud container to ${TARGET_DATA_DIR} ..."
+  docker exec "${APP_CONTAINER}" sh -lc 'cd /var/www/html/data && tar -cf - .' | \
+    docker run --rm -i -v "${TARGET_DATA_DIR}:/to" alpine:3.20 sh -lc 'cd /to && tar -xf -'
+fi
+
+echo "==> Normalizing ownership and permissions on target data directory..."
+docker run --rm -v "${TARGET_DATA_DIR}:/to" alpine:3.20 sh -lc '\
+  chown -R 33:33 /to && \
+  find /to -type d -exec chmod 0750 {} + && \
+  find /to -type f -exec chmod 0640 {} + && \
+  touch /to/.ocdata && \
+  chown 33:33 /to/.ocdata && \
+  chmod 0640 /to/.ocdata\
+'
+
+echo "==> Updating compose app volume mapping to use external data directory..."
+python3 - "${COMPOSE_FILE}" "${TARGET_DATA_DIR}" <<'PY'
+from pathlib import Path
+import sys
+
+compose_file = Path(sys.argv[1])
+target = sys.argv[2]
+lines = compose_file.read_text().splitlines()
+
+try:
+    app_idx = next(i for i, line in enumerate(lines) if line.startswith("  app:"))
+except StopIteration:
+    raise SystemExit("ERROR: Could not find 'app' service in compose file")
+
+app_end = len(lines)
+for i in range(app_idx + 1, len(lines)):
+    line = lines[i]
+    if line.startswith("  ") and not line.startswith("    ") and line.endswith(":"):
+        app_end = i
+        break
+
+try:
+    volumes_idx = next(i for i in range(app_idx + 1, app_end) if lines[i].startswith("    volumes:"))
+except StopIteration:
+    raise SystemExit("ERROR: Could not find volumes block in app service")
+
+items_start = volumes_idx + 1
+while items_start < app_end and lines[items_start].strip() == "":
+    items_start += 1
+
+items_end = items_start
+while items_end < app_end and lines[items_end].startswith("      - "):
+    items_end += 1
+
+new_line = f"      - {target}:/var/www/html/data"
+updated = False
+for i in range(items_start, items_end):
+    if lines[i].strip().endswith(":/var/www/html/data"):
+        if lines[i] != new_line:
+            lines[i] = new_line
+        updated = True
+        break
+
+if not updated:
+    lines.insert(items_end, new_line)
+
+compose_file.write_text("\n".join(lines) + "\n")
+print("Updated compose file with app data bind mount")
+PY
+
+echo "==> Recreating Nextcloud app/web services with new mount..."
+compose up -d app web
+
+if ! wait_for_occ; then
+  echo "ERROR: Nextcloud did not become ready after restart."
+  exit 1
+fi
+
+echo "==> Disabling maintenance mode..."
+docker exec --user www-data "${APP_CONTAINER}" php occ maintenance:mode --off >/dev/null
+maintenance_enabled=0
+
+echo "==> Verifying effective datadirectory and mount..."
+docker exec --user www-data "${APP_CONTAINER}" php occ config:system:get datadirectory
+
+docker inspect "${APP_CONTAINER}" --format '{{range .Mounts}}{{if eq .Destination "/var/www/html/data"}}{{println .Destination "<-" .Type ":" .Source}}{{end}}{{end}}'
+
+echo "==> Migration complete."