Using recovery modes
Ubuntu Core 20 is inherently robust. But if data-corruption issues do occur, even on boot or data partitions, it can still access a recovery mode to help repair, restore or reinstall an impaired device.
These recover modes can be accessed in three different ways:
Start or reboot the device with the ‘1’ key held on a connected keyboard
snap rebooton the device with either
Snapd REST API:
Use the REST API to call either the `recover’, ‘install’ or ‘reboot’ functions.
Note: Device manufacturers using Ubuntu Core 20 may choose to implement alternative methods to access recovery functionality. These will be specific to those devices.
To access the recovery chooser, start or reboot the device with the ‘1’ key held on a connected keyboard. If the chooser fails to launch, try pressing 1 repeatedly from boot. It needs to be captured by Ubuntu Core boot process.
After the initial boot process completes, a status screen will appear showing “System mode selection triggered. Proceed to select one of the available systems and actions.”
The menu system requires that you tab or cursor to highlight your chosen option. Ensure ‘OK’ is highlighted and press Enter to continue, after which you’ll be presented first with the recovery chooser and the option to either run normally, enter recovering mode, or reinstall.
Selecting an option followed by ‘Confirm’ will reboot the device into the selected mode (see below).
sudo snap reboot to reboot the system, the following arguments can be added to select a recovery mode with or without an additional system label for the target system:
The recover and run modes are only available for the current system.
When called without a system label, reboot will use the current system to enter the given mode. System labels are listed with the
snap recovery command:
$ sudo snap recovery Label Brand Model Notes 20201117 <user-name> ubuntu-core-20-amd64 current
To reboot the above system into recovery mode, for example, enter the following:
$ sudo snap reboot --recover 20201117 Broadcast message from root@ubuntu (Wed 2020-11-25 13:15:51 UTC): reboot scheduled to update the system The system is going down for reboot at Wed 2020-11-25 13:25:51 UTC! Reboot into "20201117" "recover" mode.