Make sure that any of following function is enabled at your server (Most server support any of this function)

  1.  PHP proc_open and shell_exec  function
  2. Zip Archive function
  3. PCL ZIP  function



Also make sure that you have either MYSQL DUMP is enabled at your server.

If you have large site, make sure you have option 1 Proc_open and shell_exec  function works at your server, this method runs for longer time instead of php zip methods that get timed out in 30 mins (depend on execution time)