Patent ID: 7225317

Claim:
A method for managing use of memory in a system of one or more storage area networks including an intelligent multi-protocol switch (IMPS) combined with a storage and switch controller including at least one microprocessor and a disk array for storing meta-data related to the plurality of data storage volumes such that the one or more data storage networks are managed by the storage and switch controller using the meta-data and by controlling the IMPS, wherein the method comprises the steps of: using memory in the storage and switch controller to supplement the memory of the IMPS by storing in the IMPS a subset of a full set of extent maps for data volumes handled by the IMPS, and storing protection maps in the memory of the storage and switch controller that mark edges of unmapped regions of the data volumes then selectively loading more than the subset of extent maps in the IMPS in response to host access to the data volumes.