Optimizing thin provisioning in a data storage system through selective use of multiple grain sizes

Abstract

A data storage system includes a pre-cache and a plurality of storage devices across which a data storage array is distributed. In response to receipt of a write request specifying a logical address and write data, the data storage system buffers the write request among a plurality of write requests in the pre-cache without provisioning in the data storage array a physical extent corresponding to the logical address. A management node analyzes the plurality of write requests buffered in the pre-cache. In response to the analyzing identifying a first pattern of write requests, the management node provisions, in the data storage array, a first physical extent having a smaller grain size and destages the write data to the first physical extent. In response to the analyzing identifying a second pattern of write requests, the management node provisions a second physical extent having a larger grain size and destages the write data from the pre-cache to the second physical extent.