A computer-readable medium storing a data management program makes a computer manage data redundantly stored in storage devices having storage areas split into slices for data management. The data management program realizes the following functions in the computer. A first function receives irregularity information indicating that each of one or more of the storage devices may be possibly faulty, and stores the irregularity information in a storage; and a second function determines, by reference to the irregularity information, whether or not a first storage device containing a slice to be accessed is possibly faulty, on receipt of access information indicating occurrence of a request to access the slice. When yes is determined, the second function instructs an external device to recover data stored in the slice, where the external device controls a second storage device storing redundant data identical to the data stored in the slice.