1. A method for avoiding a cache full condition in a dataset partitioned, page oriented cache of a defined capacity having dynamic resource allocation and intercoupling a processor to an external storage subsystem, said processor including means for storing pages of a dataset into a plurality of cache partitions, comprising the steps of: (a) periodically determining the target size of each partition for optimal partitioning; (b) assigning a reclaim vector to each partition specifying the number of frames to be stolen from each of the other partitions necessary to achieve a corresponding target size; (c) if the target size of a particular partition is less than the partition's virtual minimum size, adjusting that partition's reclaim vector to enable the partition to steal sufficient frames from other partitions to achieve the virtual minimum size; and (d) responsive to one or more page cache miss references, stealing one or more frames from other partitions, as directed by the reclaim vector of the partition storing the dataset to which the missed page reference is a member, and adding the resulting frame to the storing partition, and modifying the storing partition's reclaim vector to reflect the pages stolen.