Patent ID: 8001318

Claim:
A storage system for storing client data, the storage system comprising: at least one low-latency random read memory (LLRRM) device, the LLRRM device comprising a plurality of active erase-units that store client data and a plurality of free erase-units that do not store client data; active and free wear count (WC) data structures, the active WC data structure comprising an entry for each active EU in the LLRRM device, the free WC data structure comprising a plurality of entries for a plurality of free EUs in the LLRRM device, each entry in the active and free WC data structures comprising a wear count associated with an EU, the wear count indicating a number of erase cycles performed on the EU; and a wear leveling module executed by a processor, the wear leveling module configured for: selecting a pair of EUs for performing wear leveling, the selected pair comprising an active EU and a free EU that are selected based on the information in the active and free WC data structures; and performing wear leveling on the selected pair by copying client data from the active EU to the free EU.