稍微提一下在OS上的講解「Reliability is a measure of the continue of theservice accomplishments or the time to fail -from a reference point .Hence ,the "mean time to fail of disk is a reliability ".」 這是紅算盤的講解從這裡可以得知 reliability 與Availability 有關聯因availability =MTTF/(MTTF+MTTR)有趣的是 關於reliability 的敘述在紅算盤中就沒了反而是恐龍本有些著磨「The MTTF of a single disk is 10000 hours .Thenthe MTTF of some disk in array of 100 disks willbe 10000/100」可得知MTTF 是用來測量reliability 用的而RAID 是改善reliability 的方法之一 畢竟恐龍本上面專寫一篇講解 使用mirroring 即可改善