Note that the listed probabilities of surviving N-disk failures are not correct, though after calculation, though the differences may not be that important. Li

Note that the listed probabilities of surviving N-disk failures are not correct, though after calculation, though the differences may not be that important. Listed survival probability of N-disk failure in 8-drive/4-vdev mirror. 1: 1; 2: 0.857; 3: 0.667; 4: 0.400; 5: 0; 6: N/A; 7: N/A; 8: N/A Proper survival probability: 1: 1; 2: 0.857; 3: 0.571; 4: 0.229; 5: 0; 6: 0; 7: 0; 8: 0 Comparatively, survival probability for 8-drive RAIDz4 with equal amount of usable space: 1: 1; 2: 1; 3: 1; 4: 1; 5: 0; 6: 0; 7: 0; 8: 0 Personally, I'd use multi-vdev mirror pools only for data that is either backed-up or data I can afford to lose completely.