mv backup.3 backup.tmp
mv backup.2 backup.3
mv backup.1 backup.2
mv backup.0 backup.1
mv backup.tmp backup.0
cp -alf backup.1/. backup.0
rm -f backup.0/backup_date
touch backup.0/backup_date
nice -n 15 rsync -a --delete -e "ssh" root@host.name:/DISK2 backup.0/