[root@localhost backup_trials]# rsync -a --delete /etc/ backup.0/
[root@localhost backup_trials]# ls
backup.0
[root@localhost backup_trials]# du -h --max-depth=1
57M     ./backup.0
57M     .
[root@localhost backup_trials]# cp -al backup.0 backup.1
[root@localhost backup_trials]# du -h --max-depth=1
57M     ./backup.1
8.7M    ./backup.0
66M     .
[root@localhost backup_trials]#