Updating your system

System updates are a separate, deliberate act from app updates — one command, one reboot, and a way back if you need it.

Two kinds of update

They are independent. Updating your apps does not change the system, and updating the system does not touch your apps.

Checking for a system update

$ immos-update check
Current: 0.2.0
Available: 0.3.0

Applying it

$ immos-update apply
→ Verifying manifest signature… ok
→ Downloading immos_0.3.0 (3.9 GB)… ok
→ Writing to free slot… ok
→ Staged 0.3.0 for next boot.
  Reboot to apply.

Nothing has changed about the system you are running at this point. You are still on 0.2.0, with 0.2.0’s kernel and applications, until you reboot. Finish what you were doing and reboot when it suits you — or let immos-update reboot do both.

What happens at the reboot

The bootloader starts the new version, with three attempts allowed. Reaching a working desktop marks it good permanently. Three failures in a row and it falls back to 0.2.0, whose image never left the disk. See snapshots and rollback.

Automatic updates

Scheduled background updates are shipped but switched off by default in this release, so nothing downloads or installs unless you ask. Enabling them is:

$ sudo systemctl enable --now systemd-sysupdate.timer

The intent is to make this the default once the update path has more mileage on it — see the roadmap.

What the download costs

A system update is a full image, roughly 4 GB compressed, rather than a set of deltas. That is the current trade for the simplicity of “one image, verified as a whole”. Delta updates are a roadmap item; until then, updating over a metered connection is worth thinking about.

If a download fails

Nothing happens. A truncated or corrupted download fails its checksum, an unsigned manifest is refused outright, and in both cases the free slot is left alone and your running system is untouched. Run immos-update apply again when you have a better connection.