Update DSM on the DS220+ manually and follow the release-note cautions:
- If auto update does not run, do a manual update in Control Panel.
- Before updating, complete the required actions in the update instructions.
- If you want the latest version now, go to Synology Download Center and manually update DSM.
- For a clean installation, use find.synology.com or Synology Assistant 7.0-50029 or above.
- DSM 7.0 and later cannot be downgraded after installation.
- DSM update may take 10–20 minutes, and package updates can take more than an hour.
If you prefer CLI, the available commands are:
- sudo synoupgrade --check
- sudo synoupgrade --download
- sudo synoupgrade --start
- sudo synoupgrade --auto
- sudo synoupgrade --patch /{{path/to/file.pat}}
Sources used: [5], [6], [8]