It is sometimes possible to predict a disk failure based on a pattern of recovered errors that have occurred. In such cases, the disk reports a predictive failure.
the system initiates Rapid RAID Recovery to copy data from the failing disk to an available spare disk. When data is copied, the disk is marked as failed and placed in the pool of broken disks
So Predict failure is nothing but the disk has been failed. You can directly go and replace that disk with new one 🙂