Caching techniques for use in a computer system comprising a core and at least one edge device. The core comprises at least one object addressable storage system. At least one cache is disposed logically between the core and the edge device. The cache has a prefetch policy that selects from among the content units based upon at least one prefetch criterion. The prefetch policy imposes a limit on at least one prefetch operation. The limit is selected from the group consisting of: a total number of content units to be prefetched; a time range during which content units were stored to qualify as prefetch candidates; and a total volume of content to be prefetched.