Instances on Exoscale are designed to boot from their direct attached SSD disk, also known as root disk. It can happen that during a major upgrade of the system or while modifying the partition layout or bootloader that the instance cannot boot normally anymore.
To that purpose, a Rescue Mode exists in order do get an access to the root disk of the machine by booting from a different source. The boot program used in this case is the open source project called Netboot and allows to start a variety of Linux, BSD or specialized installers or utilities.
Rescue mode pre-requisite
As Rescue Mode is not a default operation, it requires:
- a working
- access to your account API key
- access to the Exoscale portal
Booting into Rescue Mode
To reboot in Rescue Mode, first start by shutting down your instance. This can be performed via the CLI or via the portal in the instance details:
exo vm stop broken-vm
Then start the instance in Rescue Mode
exo vm start --rescue-profile=netboot broken-vm
The instance will now boot the Netboot image.
Accessing the rescue mode
To access the rescue mode, launch the Exoscale portal and navigate to the instance detailed view. Once on the detailed view, click the OPEN CONSOLE button.
A new window will open and display the instance screen and the Netboot menu will appear:
Perfom the operation you require in the instance - those are outside of Exoscale support perimeter - and finally reboot your instance.
Once rebooted the instance will exit Rescue mode and try to boot from the root disk.