Methods and systems are disclosed that relate to locating cached data
corresponding to data in persistent memory within a data storage
facility. An exemplary method includes receiving a request for data in
persistent memory, applying a function to a persistent memory address of
the requested data to determine an address of one of a plurality of cache
tag controllers, each of which controls nonduplicative cache tags, and
looking up, at the addressed cache tag controller, a cache memory address
for data corresponding to the requested data.