稍微提一下在OS上的讲解“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 ".” 这是红算盘的讲解从这里可以得知 reliability 与Availability 有关联因availability =MTTF/(MTTF+MTTR)有趣的是 关于reliability 的叙述在红算盘中就没了反而是恐龙本有些著磨“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 是用来测量reliability 用的而RAID 是改善reliability 的方法之一 毕竟恐龙本上面专写一篇讲解 使用mirroring 即可改善