When an update is complete, the previous OS deployment remains on disk. If an update causes issues, you can use it as a fallback. This is a manual operation that requires human intervention and console access.
To temporarily boot the previous OS deployment, hold down
Shift during the OS boot process. When the bootloader menu appears, select the relevant OS entry in the menu.
To permanently revert to the previous OS deployment, log into the target node and run the following commands:
# Stop the service that performs automatic updates sudo systemctl stop zincati.service # Mark the previous OS deployment as the default, and immediately reboots into it sudo rpm-ostree rollback -r
Please note that Zincati will keep looking for updates and upgrade to any new available OS deployment, other than the one you just reverted.
If you prefer, you can temporarily turn off auto-updates. Later on, you can re-enable them in order to let the machine catch up with the usual flow of updates:
# Disable Zincati in order to opt-out from future auto-updates sudo systemctl disable --now zincati.service [...] # At a later point, re-enable it to re-align with the tip of stream sudo systemctl enable --now zincati.service