How do I choose the Stable or Beta update channel and set a maintenance window?

Availability

The update channel, the explicit automatic-update switch and the maintenance window were added to the updater after build v278 (committed 2026-11-16) and are not part of the shipped build yet. Until they ship, Settings → Software updates offers only the three policies Off, Notify and Automatic. See Software updates settings. This article describes what the next release adds.

The controls

In Settings → Software updates:

• Check for software updates (a switch): off means the policy Off (no checks, no downloads, no installs).
• Install updates automatically (a switch): off means Notify (you approve each release); on means Automatic.
• Release channel card: choose Stable or Beta.
• Maintenance window card: Only install automatically during a maintenance window, with a start time, an end time and a time zone, and Save maintenance window.

Stable and Beta

The server tells the licence service which channel you chose with every licence request, and the licence service decides what it offers. The offer travels inside the signed lease, so a switch takes effect once the licence service has issued a lease for the new channel. BackupWall asks for one at once; if it cannot, the next 6-hourly check-in does. Until then, the page says "Switched to the Beta channel. The licence service is being asked what it offers there; this takes a few minutes, and nothing from the previous channel is installed in the meantime." So switching from Beta to Stable can never install a Beta release that was downloaded earlier. An older policy file with no channel reads as Stable.

Maintenance window

A maintenance window limits automatic installs to a time range.

1. In Settings → Software updates, open the Maintenance window card and switch on Only install automatically during a maintenance window.
2. Enter a start and an end time in 24-hour form (HH:MM, for example 02:00 and 05:00).
3. Choose a time zone (an IANA name such as Europe/Berlin or UTC), or leave it empty to use the server's own zone.
4. Choose Save maintenance window.

Rules:

• The start is inside the window, the end is not. A start later than the end crosses midnight: 22:00 to 04:00 is open from 22:00 until 03:59 the next morning.
• A start equal to the end is refused.
• With no window set, an automatic install can happen at any time.
• The window holds back only the automatic install. Checking, downloading and notifying are never held back, an administrator's own approval in Notify mode installs without waiting for the window, and a manual root apply and crash recovery ignore it.
• Inside the window, an install still waits until no backup, restore, migration or download is running, and tries again every 5 minutes until the window closes.
• A window that cannot be understood (a bad time, an unknown zone) counts as closed, so a bad setting can only delay an automatic install, never let one through at the wrong time. The page then says the release "will not be installed automatically: the maintenance window cannot be used".
• When a release is downloaded and waiting, the page says "<version> is downloaded and waits for the maintenance window (02:00 to 05:00 Europe/Berlin)."

From the command line

cd /opt/backupwall
.venv/bin/python -m app.updates policy automatic --channel stable \
  --window on --window-start 02:00 --window-end 05:00 --window-tz Europe/Berlin

--channel stable|beta, --window on|off, --window-start HH:MM, --window-end HH:MM and --window-tz NAME|default set the channel and window; what you do not pass stays as it is. The API takes the same fields on PUT /updates/policy.