allocated_size : 64 : littleendian; (* allocate size on disk *)
data_size : 64 : littleendian; (* byte size of the attribute *)
initialized_size : 64 : littleendian;
allocated_size : 64 : littleendian; (* allocate size on disk *)
data_size : 64 : littleendian; (* byte size of the attribute *)
initialized_size : 64 : littleendian;