The invention relates to the field of fault detection, in particular to a
disk array fault detection method and device. The method mainly comprises the steps of calculating a
prior probability of a fault according to a
failure rate of a circuit module; determining a
target signal influencing a working state in the
disk array, collecting an original sample of the
target signal, obtaining a secondary sample under a fault condition in the original sample, and calculating an original
conditional probability of the corresponding
target signal according to the secondary sample; establishing a multi-factor model containing all target signals, and calculating a fault threshold value by using the multi-factor model based on the original
conditional probability; and in the running process of the
disk array, collecting alarm values of the target signals when the alarm signals are generated, forming alarm samples by the alarm values in a specified time period, calculating the
posterior probability corresponding to each alarm sample, and judging the working state of the disk array in the corresponding time period according to the fault threshold and the
posterior probability. According to the method, the false early warning rate can be reduced, and the
RAID reliability and availability are improved.