GPT_PARTS_PER_SEC
num = ((MD_GPT_INITIAL_SIZE-(2*512))/512)*GPT_PARTS_PER_SEC;
*head = 2 + num/GPT_PARTS_PER_SEC;
*tail = 1 + num/GPT_PARTS_PER_SEC;
parts->max_num_parts = p_size * GPT_PARTS_PER_SEC;