code: def umount(self, source):
          
  
          args = {
              'source': source,
          }
          self._umount_chk.check(args)
  
          response = self._client.raw('disk.umount', args)
  
          result = response.get()
  
          if result.state != 'SUCCESS':
              raise RuntimeError('failed to umount partition: %s' % result.stderr)
docs: Unmount partion
          :param source: Full partition path like /dev/sda1