system-backup provides read-only access to the system via /var/lib/snapd/hostfs. This interface gives privileged access to system data.
Auto-connect: no
Transitional: no
Requires snapd version 2.43+.
By design, snaps using strict and devmode confinement run with a different root filesystem than the host. Snaps that implement a backup function, however, need access to the host’s snap-related files outside of this confinement, and this is where the system-backup interface can help.
The system-backup interface provides read-only access to files under the following location:
/var/lib/snapd/hostfs
With the following exceptions:
/var/lib/snapd/hostfs/dev/var/lib/snapd/hostfs/proc/var/lib/snapd/hostfs/sys
Importantly, neither snapd nor this interface provide any mechanisms to ensure the system is in a ready state for backups. Reliable backup strategies with snaps utilising this interface will need to account for this themselves.
ⓘ This is a snap interface. See Interface management and Supported interfaces for further details on how interfaces are used.