An in-memory cache for a computer system having a first storage and a second storage where the first storage is a cache for the second storage, tracks priority levels of block attributes stored therein. If a data item is cached in the first storage, the block attribute corresponding to the data item is stored in the in-memory cache as a high priority block attribute. If a data item evicted from the first storage, the block attribute corresponding to the data item is stored in the in-memory cache as a low priority block attribute. When the cache becomes full, the low priority block attributes are evicted before the high priority block attributes.