0 votes 0 votes A RAID can fail if two or more of its drives crash within a short time interval. Suppose that the probability of one drive crashing in a given hour is $p.$ What is the probability of a $k$-drive RAID failing in a given hour? Operating System tanenbaum operating-system input-output disk descriptive + – admin asked Oct 28, 2019 admin 1.2k views answer comment Share Follow See all 0 reply Please log in or register to add a comment.
0 votes 0 votes Answer: The probability of $0$ failures, $\mathbf {P_0}: $$(1-\mathrm p)^{\mathrm k}$ The probability of $1$ failures, $\mathbf {P_1}: $$\mathrm{kp}(1-\mathrm p)^{\mathrm k-1}$ $\therefore$ Probability of a $\mathbf{RAID}$ failure $=1-\mathrm {P_0}-\mathrm{P_1} = 1-(1-\mathrm p)^{\mathrm k}-\mathrm{kp}(1-\mathrm p)^{\mathrm k-1}$ `JEET answered Oct 29, 2019 `JEET comment Share Follow See all 0 reply Please log in or register to add a comment.