An improved technique for a data storage apparatus that combines both block-based and file-based functionality in a unified data path architecture. The improved technique brings together IO processing of block-based storage systems and file-based storage systems by expressing both block-based objects (e.g., LUNs) and file-based objects (e.g., host file systems) in the form of files. These files are parts of an underlying set of internal file systems stored on a set of storage units served by a storage pool. Because block and file-based objects are all expressed as files of this set of internal file systems, a common set of services can be applied across block-based and file-based objects. In particular, enhanced data services such as compression, automated storage tiering and deduplication are provided across both types of object using one set of common mechanisms.