Technical solutions are described to forestall data loss caused by wearout of storage disks in an array of storage disks in a storage system by monitoring a rate of writes for a first storage disk in the array and determining a mean time to failure of the first storage disk. A start time is determined based on the mean time to failure, a number of storage disks in the array, and a time to replace a storage disk in the array. At the start time, a notification is issued as an alert to replace the first storage disk to forestall data loss caused by wearout of a second storage disk in conjunction with a wearout of the first storage disk.