在计算机报上看到荷兰银行的20个数据中心有大约7pb磁盘和超过20pb的磁带存储，而且每年50%~70%存储量的增长，
于是想看看pb究竟有多大，计算一下27pb大约为 40万个80的硬盘大小。
1Byte = 8 Bit
1 KB = 1,024 Bytes
1 MB = 1,024 KB = 1,048,576 Bytes
1 GB = 1,024 MB = 1,048,576 KB = 1,073,741,824 Bytes
1 TB = 1,024 GB = 1,048,576 MB = 1,073,741,824 KB = 1,099,511,627,776 Bytes
1 PB = 1,024 TB = 1,048,576 GB =1,125,899,906,842,624 Bytes （13107.2个80G的
1 EB = 1,024 PB = 1,048,576 TB = 1,152,921,504,606,846,976 Bytes
1 ZB = 1,024 EB = 1,180,591,620,717,411,303,424 Bytes
1 YB = 1,024 ZB = 1,208,925,819,614,629,174,706,176 Bytes