Deduplication of data on distributed storage system involving receiving and modifying metadata from local object store

An aspect of performance optimization in a storage system environment includes providing a metadata structure that describes a storage space of a storage system. For each storage object of a plurality of storage objects, an aspect includes monitoring input/output (IO) patterns for IO operations conducted, monitoring deduplication characteristics of the storage object, and configuring local mapping layer parameters. An aspect further includes modifying local object metadata in the metadata structure as a function of the monitoring and the configuring.