d.write(self.mbr.pack())
d.write(self.primary.pack())
d.write('\x00' * (BLOCKSIZE - self.primary.size()))
+ d.write(self.part_entries)
d.seek(self.secondary.part_entry_start * BLOCKSIZE)
d.write(self.part_entries)
d.seek(self.primary.backup_lba * BLOCKSIZE)