Para backup incremental de rsync, use a ferramenta rsnapshot.
Exemplo de rsnapshot.conf
snapshot_root /backup
cmd_cp /bin/cp
cmd_rm /bin/rm
cmd_rsync /usr/bin/rsync
cmd_ssh /usr/bin/ssh
cmd_logger /usr/bin/logger
cmd_du /usr/bin/du
cmd_rsnapshot_diff /usr/bin/rsnapshot-diff
retain daily 7
retain weekly 4
verbose 2
loglevel 3
logfile /var/log/rsnapshot.log
lockfile /var/run/rsnapshot.pid
backup root@localhost:/etc/ localhost/
backup root@localhost:/home localhost/
backup root@localhost:/var/www/ localhost/
Definir Cronjobs Para backup automático:
# m h dom mon dow command
#Run Rsnapshot At 02:00 Everyday
00 02 * * * /usr/bin/rsnapshot daily
#Run Rsnapshot At 06:00 Every Sunday
00 06 * * 0 /usr/bin/rsnapshot weekly