'Preallocate file blocks by writing zeros.'

def _allocate_file_blocks(self, path, size):

    block_size_mb = 1
    block_count = ((size * units.Gi) / (block_size_mb * units.Mi))
    self.gpfs_execute('dd', 'if=/dev/zero', ('of=%s' % path), ('bs=%dM' % block_size_mb), ('count=%d' % block_count))
