In this exercise, we will investigate the mean time until data loss (MTDL). In RAID 4, data is lost only if a second disk fails before the first failed disk is repaired.
a. What is the likelihood of having a second failure during offline reconstruction?
b. Given this likelihood of a second failure during reconstruction, what is the MTDL for offline reconstruction?
c. What is the likelihood of having a second failure during online reconstruction?
d. Given this likelihood of a second failure during reconstruction, what is the MTDL for online reconstruction?