Make an archive of a plesk httpdocs directory
tar -cvzf domain.com_backup_7.17.14.tar.gz /var/www/vhosts/domain.com/httpdocs/
Result
-rw-r--r-- 1 root root 14482441 Jul 17 14:09 domain.com_backup_7.17.14.tar.gz
Extract the same file
tar -xf domain.com_backup_7.17.14.tar.gz