1. A computer apparatus comprising: a controller to: store a descriptor, the descriptor comprising a mapping of an address range of a data block in a persistent storage medium into an aperture comprising a predetermined address range that is within an accessible memory address range of at least one processor of a plurality of processors; provide a copy of the descriptor to a requesting processor of the plurality of processors; receive an amended descriptor from the requesting processor, the amended descriptor comprising a different address range of a different data block in persistent storage; and update the stored descriptor with the amended descriptor to change the aperture mapping to the different address range.