Aspects include defining a first percentage of storage areas in an array of multiple persistent storage elements as hot storage areas and a second percentage of storage areas as spare storage areas such that remaining storage areas define a third percentage as cold storage areas. Each of the storage areas are assigned to either the hot group, the spare group or the cold group, respectively. A hot and cold storage area each include a first storage block on two different storage elements, and the hot storage area and the cold storage area each include a corresponding second storage block on a storage element different to the storage element on which the first respective storage block is stored. The storage blocks are distributed across the storage elements such that blocks of storage areas with the highest write rate of all storage areas are placed on a hottest storage element.