Limits of Cinnamon Notification Controls for Update Manager Alerts in Linux Mint

Answer to the Question

Update Manager (mintupdate) cannot be configured to display only security‑level alerts while hiding lower‑priority ones. Neither Cinnamon nor mintupdate provides a quiet‑hour scheduler that targets only the Update Manager tray icon. Enabling the global Do Not Disturb mode mutes every notification, and there is no per‑application exception mechanism for mintupdate.

Confirmed Facts

• In the Update Manager preferences you will only see a Show notifications toggle and a Check interval selector.
• Cinnamon’s notification daemon honors the libnotify urgency levels (low, normal, critical) but does not expose any UI or gsettings key to filter notifications by urgency.
• The global Do Not Disturb switch is system‑wide; it cannot be scoped to a single application.
• There is no built‑in quiet‑hour scheduler for individual applications in Cinnamon.

Likely Workarounds (with Caveats)

1. Scripted DND toggling

   Schedule a cron job or systemd timer that toggles the global DND state during desired hours:

   # Enable DND at 22:00
   gsettings set org.cinnamon.settings-daemon.plugins.notifications dnd-enabled true
   # Disable DND at 06:00
   gsettings set org.cinnamon.settings-daemon.plugins.notifications dnd-enabled false
   

   This will silence all notifications, including those from mintupdate, during the quiet period. Use with caution to avoid missing critical updates.

2. Custom notification daemon

   Replace Cinnamon’s default daemon with a third‑party libnotify‑aware daemon that can filter by urgency. This requires compiling the daemon and configuring Cinnamon to use it, which is beyond typical user maintenance and may break other notifications.

3. Manual filtering

   Keep the Update Manager notifications enabled but ignore low‑priority alerts manually. This is the simplest approach but relies on user vigilance.

Verification Checklist

• Open Update Manager → Preferences and confirm only the two available options.
• Run gsettings list-keys org.cinnamon.settings-daemon.plugins.notifications to verify no per‑app or urgency keys exist.
• Trigger a low‑priority update (e.g., a non‑security package) and observe that the notification appears if DND is off.
• Enable DND and confirm that the notification is suppressed.

Missing Diagnostic Detail

Which Linux Mint release are you using? Different releases may ship slightly different gsettings schemas, and confirming the exact version will help ensure the commands above work as described.