Hi Bruno,
To restore a backup you need to run a command like this
/opt/vertica/bin/vbr.py --task restore --config-file configuration_directory_path_filename
You need to restore files (the ones you copied to an external system) to each pf the locations indicated in the backup file. If it was done locally, to the local folder on each node.
To confirm the backup files restored from the external system are ready to be restored you can run this command to list the available backups
/opt/vertica/bin/vbr.py --task listbackup --config-file configuration_directory_path_filename
Regards