Synchronous destage of write data from shared global memory to back-end storage resources

A synchronous destage process is used to move data from shared global memory to back-end storage resources. The synchronous destage process is implemented using a client-server model between a data service layer (client) and back-end disk array of a storage system (server). The data service layer initiates a synchronous destage operation by requesting that the back-end disk array move data from one or more slots of global memory to back-end storage resources. The back-end disk array services the request and notifies the data service layer of the status of the destage operation, e.g. a destage success or destage failure. If the destage operation is a success, the data service layer updates metadata to identify the location of the data on back-end storage resources. If the destage operation is not successful, the data service layer re-initiates the destage process by issuing a subsequent destage request to the back-end disk array.