Automatic Configuration Backup

Cumulus Linux provides an automatic configuration backup feature that takes snapshots each time the nv config apply command runs successfully. The switch also takes a snapshot weekly to ensure that at least one valid weekly snapshot is available, subject to disk space and backup success.

The switch stores the snapshots in the /var/lib/nvue/backup/applied directory and the weekly snapshots in the /var/lib/nvue/backup/weekly/ directory. When you reach the maximum storage limit of 512 MiB, the switch deletes the oldest snapshots and logs the deleted snapshots.

Root owns the snapshot directories; you can view the directories only if you have root privileges.
The snapshots contain potentially sensitive configuration details such as certificates, interface IDs and routing configuration, services and IP addresses.
If the nv config apply command fails verification, exits on warning prompts, or rolls back due to a --confirm timeout, the automatic configuration backup does not run.

Enable Automatic Configuration Backup

Automatic configuration backup is disabled by default. To enable automatic configuration backup, run the nv system config backup state enabled command:

cumulus@switch:~$ nv set system config backup state enabled
cumulus@switch:~$ nv config apply

To disable automatic configuration backup, run the nv system config backup state disabled command.

Restore a Snapshot

To restore a snapshot, identify the snapshot you want to restore by inspecting the /var/lib/nvue/backup/applied/ directory or the /var/lib/nvue/backup/weekly/ directory, then run the nv action system config backup restore <snapshot-id> command.

cumulus@switch:~$ nv action system config backup restore /var/lib/nvue/backup/weekly/weekly-20260320-121030

The configuration restore process triggers a controlled reboot so that all relevant services and daemons restart with the restored configuration.

Backup and Restore Errors

If the backup or restore fails, you see errors.

Configuration Backup Errors

If the automatic configuration backup results in failure, the nv config apply command completes; however, you cannot retry the configuration backup with the same nv config apply command.

If the weekly automatic configuration backup results in failure, the error is recorded in the logs and the next scheduled run proceeds normally. To view the logs, run the journalctl -u nvue-config-backup-weekly.service command.

If the automatic configuration backup reports insufficient space, the switch deletes the oldest snapshots. If the there is still a failure, the switch logs the error and skips the snapshot.

Configuration Restore Errors

If you encounter an error when restoring a snapshot, inspect the logs and attempt to restore another snapshot.