Machines' backups are executed manually by operators after every significant change.
4 USB disks are stored at the Medicina station with labels on them indicating which of the 4 machines they backup, each disk is partitioned exactly as the original one and can be substituted in the server for a quick reboot in case of failures.
For executing the backup simply connect the USB disk to the corresponding machine and run:
[root@escsSomething]# ./root/bin/doBackup
This will invoke rsync on each significant filesystem partition. if run with --boot option the script will also add labels to the filesystems, and this should be done only during the first backup operation on the disk.