DATA STORAGE SYSTEM AND PROCESS FOR DATA COMPRESSION OF DISTRIBUTED DATA IN A SCALABLE CLUSTER SYSTEM AND COMPUTER PROGRAM FOR SUCH DATA STORAGE SYSTEM

The present disclosure relates to storing a data object to one or more storage devices of the data storage system in units of data blocks; storing a metadata structure for the data object including one or more direct metadata nodes, and optionally including a root metadata node and optionally further including one or more indirect metadata nodes, each direct metadata node including block pointers referencing respective data blocks of the respective data object; dividing the data object into plural compression units; compressing each compression unit of the plural compression units to a respective compressed unit associated with the respective compression unit; modifying, for each compression unit, block pointers of the direct metadata node referencing respective data blocks of the respective compression unit on the basis of the associated compressed unit; and managing I/O access to the data object based on the metadata structure of the data object.