Of course, after a total machine crash, you will have your backups at hand, but what should you do with it ?

Here is the restoration procedure:

How to restore a Rudder backup. 

# First, follow the standard installation procedure, this one assumes you have a working "blank"
# Rudder on the machine

# Disable Rudder agent
rudder agent disable

# Stop Rudder services
service rudder stop

# Drop the OpenLDAP database
rm -rf /var/rudder/ldap/openldap-data/alock /var/rudder/ldap/openldap-data/*.bdb /var/rudder/ldap/openldap-data/__db* /var/rudder/ldap/openldap-data/log*

# Import your backups

# Configuration repository
tar -C /var/rudder -zvxf /root/rudder-backup-XXXXXXXX.tar.gz

# LDAP backup
/opt/rudder/sbin/slapadd -l /root/rudder-backup-XXXXXXXX.ldif

# PostgreSQL backup
sudo -u postgres psql -d rudder < /root/rudder-backup-XXXXXXXX.sql
# or
psql -u rudder -d rudder -W < /root/rudder-backup-XXXXXXXX.sql

# Enable Rudder agent
rudder agent enable

# And restart the machine or just Rudder:
service rudder restart